760 DR. R. BROOM ON TIUTYLODON [Mtty 3,

Zonocypria Irevia U. 0.Gars. Fig. 4. Ahlt frmnle, viewed from right side. 6. Sitme, dorsal view. 6. Mii~iil~rimpreasions of right valve. 7. Extremity of left inferior aiiteniin.

StenorJ/p,.ispeinvinntn 13rarlS. Pip;. A. Adnlt feinsle, viewed froui right side. 9. Saine, dorsal view. 10. C’nodal rami. Heteroryprie dubia G. 0.Sara. Fig. il. Adrilt female, viewed froin right side. 12. Same, dor*nl view. 1% Yiisanliir iinpreasioiis of right valvt~. 1.1.. C‘illldal ralll~ls.

PLATE LXX I I r. II!j~i:yprispmpbqna G. 0.Snra. Fig. 1. Adult frmale, Tiewed from left side. 2. Sume, dorsal view. 3. Ma=ciilar iin~iressioiisof left vdve.

4. Candal ramiis. 4 Ilyorypvis nlta G. 0.Sarn. Pig. 6. Adiilt iiiale, viewed from left side. 6. Same, dorsal view. 7. Caudal ramils. Limnic.t/there obturntn G. 0. Sara. Fig. R. Adiilt fem:ile, viewed from right side. 9. Same, dorsal view. 10. Muvcnlar impressions of right valve. 11. Superior anteniia. 1% Iiifrrior antenna. 13. Right series of legs. 14. C’aiidd lobe. Pnmcypria rttrtn Q. 0.Rnrs. Fig. 16. .kdidt, inale, viewed from right side. 16. Same, dorsal viiw. 17. Caudal ramus.

6. On ‘I’rh!/loiEon, and on the 1~el:itionshipsof the iMiiltitu’uerculnta. By 11: BROOM,M.D., D.Sc., ( 3f.Z.S. [Received March 14, 1910.1 (Text-figureh 67 and 68.) In 1884 Owen described, iinder the name 5!’vit?/lmZon lonyc~~~~cs, H very reinarkable imperfect skull submitted to hini by Kk. Extoll, of the Bloeinfontein Museum. The specimen WHIS stated to have come from ‘‘ Thaba-chou, Hasutoland,” and was believed to be it Triassic allied to the European Stereoynathtts. There is no locality known in Basutolancl of the name Thttba-chou, but there tire se\-er:iI nionntainh called l’haha-tsue11, and it is prohahly from one of these that the specimen came. In any ~ahewe now 1910.1 ASD THE Mb'r/rITUBBRC!ITLATA. iG1 kiiow that the whole of Basutoland is on beds of Stormberg age : and ns the Stormberg beds are situated above the Molten0 beds, which are known to be Rhstic, and as they contain remains of true Crocodiles, we may safely assume that they are of Lower Jurassic age, and not Triassic as was supposed. The specimen, which consists of the almost perfect snout with part of the interorhital region, portions of the malar arch, and the complete palate, was described by Owen at some length. and his figures have been frequently reproduced. Owen's opinion that Trit?yZodon was n niammal was supported by Cope, Obhorn, Lydekker, Seeley, and others. In 1894, however, Seeley, as the result of his examination of the reptiles, came to the conclusion that Z'ritylodon was really a slightly modified Cynodont reptile ; and this view has been followed by a number of Inter writers. Text-fig. 67.

Side view of Snout of TrifyZodon Zongmvus Owen. Nat. size. Slightly restored. Fr. Frontal. Ju. Jupl. La. Lachrymal. Hs. Maxilla. Na. Nasal. Pa. Pulntine. Pmx. Premaxilla. Sms. Septomaxilla. In 1904 I endeavoured to show that none of the arguments advanced by RPeley in favour of Z'vityZoclo?i. being a reptile were valid, hut that in all points il'ritylodo,, was an undoubted ina 111 ind 762 DR. R. BROOM OX TRITTLODON [May 3,

While recently in London I made a careful study of the type, which, unfortunately, is still the only specimen known, and found that a good deal more could be made out of the original specimen than WA~supposed. In a considerable number of points my conclusions differ from those of Owen and Seeley. The flat piece of bone on the upper part of the snout, which both Owen and Seeley believe to be the frontal, I consider without doubt the upper part of the nmal. The pair of imperfect bones, which form a median ridge at the back part of the specimen as preserved, are believed by Owen and Seeley to be the parietals. I regard them as the anterior halves of the frontals. The bone which Seeley believes to be the pre- frontal I hold to be the upper part of the large lachrymal. Text-fig. 68.

Upper view of snout of Tritylodon longgreaua Owen. 3 nat. sire. Fv. Frontal. Ju. Jugal. La. Lachrynd. Mz. Maxillu. Nu. Nasal. PIW.I’reninxilln. Smx. Septomuxilla. Owen gives the dental formula rn i 2, m 6. I believe there are pretty certitinly seven molars, and in front of the large incisors fhere is a socket which probably had a bmall anterior incisor. I therefore conclude that the formula is i3, mi. There is un- doubted evidence that, the lower molars ground with an antero- psterior motion against the upper. The lower incisp? most p&&ly passed together between the large upper incisors, which 1910.1 AND THE YULTITURERCULATA. 7G;q I believe to be i', and their tips probably rested against the small i'. Between the nasals and the premaxillaries is a pair of well- developed septoniaxillaries which have not previously been observed. The position of these bones is seen in the figures given of both side and upper views. The septomaxillary com- pletely separates the premaxillary from the nasal and passes down into the anterior nrtsitl region. There is no evidence that the nares have been beparated by a complete internasal process of the premaxillaries. When the back part of the skull and the lower jaws are restored there is presented a singularly Rodeiit-like appearawe. As regards the habits of Tritylodon, I think it most probable that it was a root-eating , the large tusk-like 2nd incisors being well adapted for digging out and breaking of the roots, and the molars with their rows of crescentic tubercles admirably suited for grinding. I'ritylodon i8 the oldest Multituberculate mammal the skull of which is known even partly, and the only other Multituber- culate of which much besides the lower jaw is known is one of the latest Eocene types, Ftilodz~s. Fortunately there has recently been discovered ant1 described by Gidley a good skull with the lower jaw in position and a number of the more important bones of the skeleton of Ptilodus yracilis. From the study of Ytilodus, Gidley comes to the following very interesting conclusions, which may be stated in his own words :- id A fwt of first importance is that neither in the skull nor skeleton of the Montana specimen are there any indications of affinities suggesting the , while every character is niarsopial, as shown in the general arrangement and function of the teeth and the developnient of the skull and skeleton. The unequal development of the f0i.e and hind limbs, the character of the inciaors, the form of the palate, and the position of the cheek-teeth all indicate definite affinities with the Diprotodonts. At the same time the reduction in numbers of the molars and the extreme specidisation of the premolars confirms Osborn's conclusion regarding the philetic position of the group, namely, that the Multitubmxhts may be the last representatives of a very ancient pliylurn that became extinct in the early Tertiary. 6' From the foregoing therefore it appeal's that the Allotheria represent an extinct group of niultituberculate Eutherian closely related with but not ancestral to the Diprotodont division of the Marsupialia, with which division they rniiy now be classed as an Infraorder, or Superfamily, their relationship dating back to H common ancestry sonlewhere in the Jurassic or even to earlier Triassic times, as was suggested by Cope." While everyone must be most grateful for the great addition made by Gidley to our knowledge of the Multituberculate struc- ture, I should like to suggest that I think the case is by no 764 DR. R. l3ROOM 0s TRITTLO1)OX [Mn:\. 3, 1iiea.m proven that they are at all closely allied to the Diplototlolit . There is a little ambiguity in his 1angua.ge w1tet.e he speaks of “ inultittiberculate Eutheriun mamnials ” forniiug an Infruorder of the Miirsupialia. Presumably he means ‘‘ Met:i.- therian.” But it is manifest he rega,rcls the Multituberculitta RS forming a division of the Marsupialia. Let us consider in sonie detail the points that are urged in favour of this conclusion. “ Every character,” it is said, “ is , as shown in the general arrangement and function of the teeth and the develop- ment of the skull and skeleton.” If by arrangement is memt the occurrence of incisors. premolars, and molars, without canines, the character is not more marsupial than , and a somewtl;lt siruilar arrangement is found in the other Eutherian orders. l3iit further the nuniber of the molars seeins to me opposed to any close association of the Multitnbercnllttes with the Marsupials. Xo living marsupial has more than three prernolitrs arid almost every one has four molars. The Multituberculittes have apparently as the normal series four premolars and three iiiolrtrs as in the Eutheria. The whole seven are seen in dh‘odon, antl wlien the number is reducer1 to six as in Ptilodzcs there seems little doirltt that the loss is in frolit and not behind. From the position of the lower teeth I should incline to the view that the large grooved tooth in Ptilodtis and the posterior of the grooved teeth in Pluyi- (su,Zaz and Ctethacodon are 1st true molars. But whatever difference of opinion may be held on the interpretation of the teeth, there can be little doubt that in structure the molars are cluite unlike anything known aniong Marsupials. In the structure of the skull the only points bearing on the affinities seem to be the folloming:--l. “The malar exteirds backward to the glenoitl surface, and apparently joins the lachry- mal bone anteriorly as in the living &l:r.rsupia~s.’’ Though the backward extension of the malar is doubtless a marsupial character it is not confined to Marsupials, being found in I’rocnvia, Mo?ri- tharium, and other Eutherians. It k a typical character of the Cyndont reptiles and was doubtless present in all early mamma.ls. The meeting of the malar and lachrynial is another Cynodont character which we sliould expect to find in my early mammal. 2. “The occiput extends but slightly beyond the posterior root of the zygoma.” This is a Cynodont character which is not met with in Marsupials *. Some approach to it is seen in some early Eutherians. 3. “ The nasals are relatively large and broad, ex- panding posteriorly.” Still another Cynodont character which is retained by most Marsupials, but also by some Eutherians, e. g. Hystriz. 4. ‘‘ The premaxillaries are short and widely separated from the frontals by the ascending portion ,of the maxilla.” This ctha.iactrr is quite common in Eutherians. 5. ‘‘ The relatively brad, high-arched palate is perforated by two pairs of foramina.”

* I3ot is found iii Or~~itho~hyynclruts. 1910.1 AND TI1E Y I; L‘l.ITU UEltC IJLATA . 765 In the palate is relatively narrow and never perfoin.ttv1. It seems probable that its mastication became established a.iid the palate became greatly widened perforation would be likely to occur. It is still found in most Marsupials, but it is also met with in Eutherians, e. g. E’I.~IMC~USand Macvoscelides. 6. ‘I There appears to be an alisphenoid canal and a well-developed alisphenoicl -bidla.” It is admitted that this region is crushed and broken, and that the characters cannot be made out clearly. So far m the figure shows, the condition is very unlike that seen in Mar- supials, and the structure of the back of the jaw confirms this. In neither Ptilodus nor Plagiutdux is there my distinct angle, and in Ctemacodon the angle is very small. This is quite unlike what is seen in Marsupials, where both in the Diprotodonts and the Polyprotodonts a well-developed angle curves round a large alisphenoid bulla. 7. “ There is a distirict notch on the inferior inner border of the [occipital] condyle, a character also observed in some of the living cliprotodont Marsupials.” The exact sliape of the occipital condyle depends much on the habits of the animal, and most of the rnarsupial peculiarities seem to be paralleled by some of the higher forms. If we knew the arrangement of the fomnina for the ixth, xth, xith, and especially xiith nerves, we would have a point of more value in settling the affinities tlian anything else connected with the skull. The lower jaw is niar- supial in having the lower posterior portion inflected, but in the pmcticrtl absence of a distinct angle it differs considerably. The humerus, it is stated, “ is distinctly eutherian throughout, and is very unlike that of any of the living Monotremes.” Thoiigli in general shape it is very unlike the humerus of either Echi&to or 0rnilhorhy)duusand bears a superficial resemblance to that of Maisupials and Eutherians, the lower end is quite unlike anything known in any living mammal, and certainly very diferent from the ordinary marsupid type. In fact, the articular portion conies nearer to the type than to that of any of the higher forms. The pelvis is too imperfect to throw much light on the affinities. The femur and tibia so far as preserved are certainly not marsupial in type, being very unlike those of eithg Diprotodonts Or Polyprotodonts *. Doubtless all the bones both of the skull and limbs are super- ficially more like those of Marsnpids than Monotremes, hut one is too apt to forget that the only living Moriotreines are de- generate dwarfed digging , aid are probably much worse types of the Prototheria than Il’dpffi and Chqsochloris itre of the Eutheris.. Taking all the points into consideration, we find that there is nothing in the postcranial skeleton that is distinctly marsupial,

* The unequal derelopiuent of the fore aiid hind linibs is a poiiit of uo weight in determiiriiig affiirities. The condition iii Macropw is probahly a very rwoit modification. A siniilar developnient is met with iii hopping airiinals of various orders, e. g. dlacroecelidee, Pedeteo, &c. pp,oc. ZOOL. 8oa.---1910, No. 1;. 5 0 766 ])TI. 11. 13110031 ON 'I'RI'I'YLOLOX ";1y 3, and in the skull only t,he inflexion of the jaw antl the palatal vacuities. All the other supposed marsupial characters are primitive fea.tures probably present in all early mammals. On the other hand, there are one or two characters strongly opposed to any association of the Multituberculata with Ma.r- supia.ls. (1) While there is no evidence of any reduction in the number of molars, there are never more than three (or according to Gidley two). In Tritylodon we seem to have the full set of four premolars and three molars. In Ctenucodon, I'luyiau,lux, and Ptilodvs we get a progressive reduction of the pren~olarsbut the molars remain constant. Further, the multituberculate con- tlition is quite unlike anything known in Marsupials. It 1na.y have been an evolution from ordinary tritubercular molars, but if Triylyphus is really Triassic then the Multituberculates a,ppearetl much before the earliest-known tritubercnli~tetypes arid niay possibly have been independently evolved from a prot,otheria.n ancestor. (2) The presence of a well-developed septomaxilla.ry in ~'1.itylodolzsuggests affinity with the Monotremes antl is opposed to a. close relationship with the Marsupials. Both E'chidnu and Omithorhynchzts, as shown by Gaupp, have large septom2txillaries. No marsupial is known to have a septomaxillary, though a small one appears to occur in Basyps, as I have shown. (3) The far backward position of the glenoid cavity is also against a marsupial affinity and in favour of the Multituberculates being a more primitive type. In Upper Triassic time we have numerous Cynodont reptiles, some so like mammals that it is often difficult to be sure whether they are mammals or not. We also have the earliest-known supposed mammals, represented by jaws with very primitive teeth. These earliest mammals can h2rdly have been other than Proto- therians, a.nd as the Multituberculates also appear to arise in the Tria.ssic and Tritylodon is certainly not later than Lower Jurassic, it seems most likely that they are an otkhoot from the early Prototherinn group. The Multituberculates anbe tra.ced right 011 to Eocene times and form a well-marked grqip with 110 close affiiiities to any other later mammals. The Marsupials of to-d:iy are appa.rently a lately evolved group which sprang from a di- phyodont placental ancestor probably in Cretaceous times. A Bidelphys-like form is perhaps the most primitive type, and from it have been derived the various Polyprotodont types, including Cceiiobstes, which for many reasons I have long looked upon as n slightly modified Polyprotodont, and later on in Aust.ralia have been evolved the Diprotodonts. If we are right in conclutling that the Diprotodont marsupials originated in Australia in Tertia.ry times from a Polyprotodont ancestor which WAY itself derived in later. Mesozoic times from a diphyodont plac~~itstl,it is difficult to believe that the Multi- txberculates which originated in Triassic times can be in any way nearly related to them. In the present state of our know- ledge it seems wisest to leave the A4ultitul.ercula.ta as a. distinct 1910.1 ASU TIIE MIiLTITUBKRCULATA. 767

independent group with no very near affinities with the living Monotremes, Marsupials, or Eutherians. About fifty years ago there was much discussion between Owen and Falconer and others as to the habits of Plagiaulaz, Oweit holding that it was a carnivore, the others that it was a vege- tarian. Since then everyone who has expressed any opinion on the subject has sided with Falconer ; aid Gidley is also opposctl to Owen. He says :-“ 7lhe evitlence t1i:Lt Z’tilodrrs :md Z’lugiu,da.r: were not cxrnivorons in 11:rhits srcwis i-a,tlirrcoiiclnsire, but as to whether they were insectivorous, hrrhivot oils, or fqyivorous there may still he some differencrs of o1)inioii. I n.m inc*lined to consider them as frugivorons since the incisors were well fitted for picking small fruits or berries, while the large irutt,ing blades of the lower premolars were admirably adapted to cutting or slicing the rinds of tough-skinned berries, or to chopping up fleshy fruits held aga.inst the blunt-pointed premolars of the upper jaw. For ma,stica.ting the seeds of such sinall fruits and berries the multitnberculate molars were amply snficient.” It has long seemed to me tha,t as with l’hylrccoleo so with Pksgimtclax, Owen wits riglit in rega.rdirig it :LS a carnivore, The large size of the temporal fossw for the acoommotla.tion of powerful temporal muscles, the small extent of the griridiiig surfwe, the cntting mechn.nism of the anterior molars or premola,rs, and the pointed condition and the mode of implanting of the incisors togetha w-ith their mode of passing between the upper incisors, all seem to me to favour a carnivorous hal.bit. An insectivorous habit, however, seems not improbable, and most sniall Carnivores a.re also pi.rtljS insectivorous. But a herbivorous liebit for siich forms a.s Plngiacclaz or Ptilodus seems to irie very improbable, and a frugivorous habit well-nigh impossible, Ptilodus from the great disparity of its limbs must have been a ground-hopping animal which was probably quite unable to climb trees. Even if it could, fruits and berries are only ripe at one or two seasons of the year, and an animal can only be ~tnatisfmtory frugivorous form if it can fly from place to place like the frugivorous bats or birds. Further, typical frugivorous forms like Aeropzts seem to require neither powerful long incisors nor large cutting inolar~ or premolars. But the most serious objection to Plagiazcluz being a frugivorous form is the fact that Ragiccdrcn: lived in Jur;r.ssio timed, whereas what, evidence there is. is a.gainst flowering phnts having been on the earth before Lower Cretaceons times. Conifers, Cycads, and Gingkoes occurred before the Cretaceous, but, so fa.r as we knon., no fruits or berries in the ordinary sense. It may be urged t1i;r.t the carnivorous mechanism of PZnginr~1rr:a is of a different type from that of modern earnivorouw nia.mnials, but there is this important point to bear in mind. Present-di3.y Carnivores almost esclusively feed on other mt-immals or birds or in some cMes fish. But the carnivorous mammals of Mesozoic times had to feed proba.hly almost exclusively on reptiles. W-ith the exceptlion of T~it~~!odnn,which wa,s prohahly ;I i.oot.-eating 53” 768 TlIE REC‘RETART 0s ADDITIOXS TO THE M9ESAUERIF. [Mny 24, animal, it is doubtful if we know of any other herbivorous type of mammal in Jurassic times. The long-jawed many-toothed small forms were probably insectivorous, the short-jawed Multi- titberculates for the most part carnivorous. The peculiar cutting premolars and molars of the latter probably were used for cutting the scaly skins of lizards, and the tubercular molars for crushing the bones. Pomibly in Eocene times they became extinct owing to the development of the Creodonts, a better carnivorous type.

Literature referred to. .R. OWEN.--“ On the Skull and Dentition of a Triassic Maminal (Tritylodon longmiws Owen) from South Africa.” Q. J. G. S. vol. XI. 1884, p. 146. H. G. SEELEY.--“T~~Repoted Mammals from the Karroo Forma- tion of Cape Colony.” Phil. Trans. 1895, p. 1025. R. BROOM.-“On the Affinities of Y’ritylodoia.” Tr. 8. Afr. Phil. SOC.vol. xvi. pt. 1, 1905, p. 73. J. W. C~IDLEY.--“ Notes on the Fossil Mammalian Genus Ptilo&s, with Descriptions of new Species.” Proc. U.S. Nat. Mus. vol. xxxvi. No. 1689, 1909, p. 611.

Mny 24, 1910. nr. HE~YWOODWARD, F.R.S., Vice-President, in the Chair. The Secretary read the following report on the additions matle to the Societyh Menagerie during the morith of April, 1910 :- The number of registered addition8 to the Society‘s Meringerie (luring the month of April last was 249. Of these 148 were acquired by presentation, 52 by purchase, 26 were received 011 tleposit, 9 in exchange, and 14 were born in the Gtirdens. The number of departures during the same period, by deaths and removals, was 158. Amongst the additions special attention may be directed to :- 1 Lar Gibbon (Hylobotes lo~),from Siam, presented on Apiil 13th by Lt. Stephen St. L. Moore, R.N. 1 Tayra (Galera barbora) and 1 Kinka jou (Cercoleptes cautli- aolvuhs), from Maniios, presented on April 14th by E. Sltlis Hrhwabe, Esq., U.M.Z.S. 1 Monk-Seal (iKonuchzcs albiwenter), from Madeira, presented on April 9th by aodfrey Williams, Esq., F.Z.S. 1 Bay Duiker (Cephalophus dorsalis), 1 Zech‘s Mole-Rat (Georychus zechi), new to the Collection, and 1 Beautiful Wood- Hawk (Dryotriorchis s$XCtabdk), from Obuassi, s. Ashanti, presented OTL April 1st by Capt. c‘. H. Armitage. P. z.s. 1910. P1. LWJ

AUDITORY APPARATUS OF BALLENOPTERA MUSCULUS. 1910.1 THE ANATOMY AXTD BIOLOGY OY TLlE LARGER CETA('N.1. 769 1 Tasmanian Wolf (Thylacim~scyitocephalm), from Tas.mnia, purchased on April 18th. 2 Bearded Vultures (Qypccetus barbuttis), from Europe, pur- chased on April 9th. 4 Mortier's Writer-I-Ieiis (Trih0~7y.cnzovtieri), from Twnxiiiti, Imrchiiserl on April 18th.

Mr Eriieht (;ihii, F.Z.S., cshibitrd :I hkin of /.'I,/;.$ ycndfiwyi a1111ninile home reni:rrks on the tlisti~ihiitioir of the aniiii>~l.

,Illre folltrwing papers were reail :-

I. INTROL)U

* (:oiniiiii:iionted by I)r. H.4N.e Gnuow, F.R.S., F.Z.S. t y0r explwiatiuii of the l'late see p. 792. 1 bor aii adniiri~hleshort accoiint of the history of wlialiiig and of its rrceiit tslilisbiiiei~tin Sco:laiid, nee two papers liy tlir Iittc Tlioiii wttish Nat. Hixt. 1!WS, vol. uiii. 1). 7i ; and Annals 6 Magi d. ivi. 1906. See alw LilIie, ?roc. C!aiiihridpe Phil. *or. 9 I(. C. Haldairc, XIIIIHISof Sciittisli XHt. kIist. 19(l4-1!#J!l.