On new Voles from the Inner Hebrides, Scotland. 361 extent of hair above and below over 4 inches; the base coloured like the back. Hab. Eastern Ecuador. Type from Sarayacu on tbe Pastasa River. Another specimen from Canelos, on the Bobonas% alt. 2100 r. T~/pe. Adult male. B.M. no. 80. 5.6. 75. Collected by Mr. (21arence Buckley. ]j'rom the dull-coloured J°h. 1. clcur of Santa Marta and Bogota this subspecies differs by its greyer Mps and the greater difference between the upper and lower extent of the hair of the tail ; but it is no doubt intermediate in character as in locality between ornatus and cicur.

XLII.--Three new Voles from t£e I~ner Hebrides, Scotland. By G. E. H. BARRETT-HAMILTOI~ and MARTIN A. C. I~INTON. IN a paper recently read before the Zoological Society we gave an account of a collection of small mamma]s from i~he Inner H~brides. This was made by Mr. R. W. Sheppard in 1912, working under the direction of Mr. W. R. Ogilvie- Grant, who organized and managed the expedition. Early in tlle present year Mr. Ogilvie-Grant arranged with Mr. D. Anderson and Mr. P. D. Montague to continue the field-work. Mr. Anderson went to the eater Hebrides and subsequently to Rum and Eigg~ while Mr. Montague visited Skye and the neighbouring islands of Raasay, Muck, and Eigg. Later, ~r. C. H. B. Grant completed the work in ~kye. The resulting collections are of great important% and when fully worked out will throw much light on several obscm-e problems. In the present note we have to describe a new species of Evotomys fi'om Raasay and. two new subspecies of the MioJ'otus agrestis group~ one flom each of the islands Eigg and Muck. 1. Evotomys erica~ sp. n. .[lab. RAASAY, Inner Hebrides. "Trapped in big heather, rather scarce " (Moldague). Material exandned. Three adult~ but no~ o]d~ males. Dimensions :-- ttead and Hind body. Tail. foot. Ear. No. 79 (type), mule, 15th April~ 1913.. 110 45 18 13 No. 80, , , ,, ,, .. 112 48 20 14"5 1~o. 81~ , 18th , , .. 114 50 20 14 362 ]~essrs. Barrett-Hamilton and ttinton on new External characters. Like E. alstonl from Mull (Abstract :P. Z. S. no. 119, 15th April, 1913, p. 18) in general appear- ance, but slightly larger and with very robust tail. Tile underside is much more heavily washed with buff, and is in sharp contrast with tlle dark-coloured flanks; the under surface of the tail is clear buff, and sharply contrasted with the dark brown of its upper side. Dentol and cranial characters. Tile cheek-teeth are of normal form, but are much larger than in _/57. alstoni or most other species of Evotomys, being scarcely smaller than those of ccesarius: ch. t. 3 * has always a deep third inner fold and usually a large iburth inner salient angle r but in no. 80 the latter is obsolete in the left tooth. The skull is most readily distinguished from that of .E. alstoni by its larger cheek-teeth, broader zygomatic arches, heavier jugals (their upper borders boldly convex), more prominent and extensive postorbital crests, less convex parietal region, wider pterygoid fossm, with correspondingly narrower choanm, and vertical instead of ventrally divergent pterygoids. The antero-internal part of each auditory bulla is produced into a blunt point instead of being rounded. The outer wall of the infraorbital canal is a little wider, the rostrum rather deeper and narrower~ with smaller and nar- rower palatal foramina, the interorbital region slightly more constricted~ and the palate relatively wider. The mandible is larger than in alstoni~ its coronold~ condylar, and angular processes noticeably more robust ; its inferior border is much thicker and the lower margin of the angle is broadened throughout into a wide surface for the insertion of the super- ficial part of the masseter muscle ; the width of this surface is 1"4 mm., but in E. alstoni only 0"4 ram. For the cranial dimensions see table on p. 363. Remarks. As we have pointed out elsewhere, E. alstoai is of interest, since in our opinion it represents in a somewhat modified form the type which in the late Pleistocene period was dominan.t in Western Europe. This type appears to have been ousted from the more favoured portions of its territory by an incoming rival, ~7. gIareol~es ; and it survives only ia islands~ on mountains~ or in the less hospitable northern districts. In each of such restricted stations i~ has suffered more or less profound modification in coping with the demands of purely local conditions~ and therefore it is now represented In this paper we write ct~. t. instead of the usual "m., because such a symbol,is non-committal ; in the opinion of one of us (see I•r.c.n Geol. Assoc. xxi. p. 490~ 1910) the anterior cheek-teeth of Microtinm are persistent "milk-molars," and the formula &n. ~ 1#~.F7.2 1.2 the correct one for the group. L~

~° 7~

v g~.., •f "~?

bDbD ~ oo ~ Condylo-basal length.

Zygomatic breadth.

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L~L~ Occipital depth (median).

¢DO0 c~,-~ ,-~ --~ Nasal length.

~ ~: ~ ¢~ -~ c~ ~ Diastema.

Upper cheek-teeth (alveolar). ~o

~ ~ ~. ~ Mandible.

Lower cheek-teeth (alveolar)•

o

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~9~ "Pu~z~o~'s~p!'eq~tt "~uuI ~¥~ uw'eS e~ZoA 364 Hessrs. Barrett-Hamilton and Hinton on new by a number of specifically or subspecifically distinct forms. Among such relicts E. alstoni is one of the least modified, and appears to have its closest ally in .E. norvegicus~ the Skandinavian representative of the ancient type. The Raasay Bank-mouse carries the story a stage furflmr. A careful analysis of the dental and cranial characters of all the available species of JF,votom~/s recently made by one of us leaves no room for doubting that E. alstoni and E. erlca are more nearly allied to each other than is either of them to any other known form. Of them~ the former is the more primitive; the latter appears to have adapted itself to subsistence upon a coarser diet than that affected by most species of JEvotomys. :For tlfis purpose the cheek-teeth have become larger and stronger; the muscles o[ the jaws have therefore acquired greater strength, and this in turn has, by demanding in- creased size and strength from those parts of the skull to which the muscles in question are a~tached, moulded the skull in a peculiar way. Thus the growth of the anterior part of the temporal muscle has caused more extensive con- striction of the interorbital region, produced longer and more prominent postorbitat crests, and stimulated growth of the upper border of the jugal. The increased development of the masseter has caused deepening of the rostrum, widening of the outer wall of the infraorbital canal, and expansion of tim zygomata, in addition to the change in the angular process of the mandible described above. To the growth of the pterygoid internus is due the widening of the pterygoid fos~m and the narrowing of the interpterygoid space; further, because of this extension the eustachian tube, in order to keep in connection with the pharynx, has grown further forwards and inwards, and so has produced the change noted in the form of the bulla.~. ~livrotus agrestis mial, subsp, n. tint. EIa(~, Inner Hebrides. " Not entirely nocturnal ; common in big heather" (Montague). Material exa,dned. Ten collected by Mr. P. D. Montague. Dimensions .N Head and Hind body. Tail. foot. Ear. No. 63, male, 30th March, 1913 ...... 108 32 ]8 13 No. 66, , 31st , ,, ...... 116 32 18"5 18 :No. 75, , 7th April, , ...... 108 34 18 13 No. 49, female~ 29th March , ...... 104 31 19"5 13 :No. 50, , 28th , ,, ...... 110 32 19 12 No. 51, ,, 29th ,, , ...... 106 32 ]9 12"5 :No. 62, ,, 30th ,, ,, ...... 103 30 19 13 No. 64(type)~female,30thMarch,1913. ]13 36 20 12 No. 65, - .... ,, - ,, 110 31 20 13 ~o. tyG , 31st , , 100 29 18 11'5 Iroles from the Inner Hebddes~ Scotland. 365

:Nine collected by Mr. D. Anderson :- Head and Hind body. Tail. foot. Ear. No. 61, real% 13th June, 1913 .... 107 39 18 13 No. 63, , 16th ,, ,, .... ]15 35 18 13 No. 64, , ,, ,, ,~ .... 110 31 17'5 12 No. 71, ,, 19th ,, , 108 36 18 13 9S aS 10 ]No. 60, female, 13th Jane~ 1913 .... ]01 85 17 12 ]No. 62, ,, ,, ,, ,, .... 116 37 18 12 No. 68, ,, 18th ,, ,, .... 116 38 19 13 No. 69, ,, ,, ,, ,, .... 112 37 17 12,

Juclging from the skulls the specimens range from imma- ture to young adult. None are really old. External characters. Having regard to tile age of tile specimens this new form agrees in size and proportions witll M. a. exs~d, from which~ however, it differs strikingly in elage. The general eolour of the back is about as in exsul, ~ ut the rump and flanks are nmch darker ; the underside and the posterior surface of each hind leg are silvery, in slmrp contrast with the dark brown of the flanks and rump. Rarely the underside shows faint traces of a median stripe of yellowish wash. Tile fur is longer and rather coarser in texture than in exsul, giving the animal a shaggy instead of a sleek appearance; this and the darkening of tile rump and flanks is due to the greater abundance and length of the black " bristle" hairs. These features are conspicuous in both vernal and mstival specimens. Dental and cranial characters. In enamel-pattern the cheek- teeth of mlal agree with those of exsul : ia the nineteen cases examined only one was entirely without a trace of the fourbh inner angle in oh. t. 1 ; in three this structure was represented merely by a microscopic vestige ; in eleven it was small but quite distinct ; and in four it was large and of regular form. l~ine skulls admit of detailed investigation : their condyle- basal lengths range between 25"4: and 27"4: mm., and the condition of their temporal ridges &e. is such as to indicate that, as in exsul and other subspecies of agrestis~ the condyle- basal length in old specimens must amount to 28"5 mm. or more. Compared with skulls of exsul of equal age, that of ,~ial agrees closely, differing only in having the nasals rela- tively a little shorter~ the auditory bullm slightly smaller, and the basioccipita], which, of course, is in close relation with tile bullm~ slightly shorter. These differences are made clear in the following table :~ 366 Messrs. Barrett-Hamilton and tIinton on new M. a. mial. M. a. exsuL 1. Condyle-basal length ...... 100 100 2. Nasal length ...... 26"2-27"3 28"0-30'0 3. Distance between condyle and molars.. 39"8-42"3 39"6-42"1 4. anterior face of bulla ...... -°8'4-29"6 29'5-31'4 5. Median length of basloecipitM...... 13"8-15"9 15 3-17'8

It is quite likely that when older skulls of mlal come to band further distinctions from e.vsul will be found ; a sugges- tion of this is afforded by the skull of the type, which has /lie parietal region flatter than in any of the numorou~ skulls of exsul before us. For the cranial dimensions see table on p. 367. Remarks. A1. a. rMal is to be regarded as a peripheral and local modification of M. a. ezsul ; in the eater Hebrides the latte U so far as is known, shows no tendency to be differentiated into local races on the various islands which i~ inhabits.

3. Microtus agrestis luch, subsp, n. [[ab. MUCK, Inner Hebrides. "Very scarce; trapped in short heather on the edge o[ the cliff" (Monta.Tue). Material examined. Three adults c311ected by ]~Ir. P. D. Montague. Dimensions :4 Head and I-I_ind body. Tail. foot. :Ear. No. 72, male, 4th April, 1913 ...... 108 32 17"5 11"0 No. 74 (type), male, 5th April, 1913.. 110 33 18 11"5 No. 73, female, 4th April, 1913 .... 105 33 18 11'0 In the skulls the temporal ridges are fused in the inter- orbital region~ and these animals are at least nearly of full size. .External characters. Size smaller than in other subspecies of agreais, nearly as in M. Mrtus. The fur is dense and stmggy, rather like that of mlal, although this character is less marked. The underside, including that of tail, has throughout a heavy wash of buff or yellow, darkened ilere and there by the slaty bases of the hairs. On the back the black "bristle" hairs are nearly as abundant and as long as in mial, and the eolour is as dark as in the latter ; laterally these hairs are fewer in number and shorter, so that ~he colour of the flanks is lighter than in the Eig'g form~ and it passes insensibly into the buff of the underside. Dental and cranial characters. The cheek-teeth are normal ; eh. t. i has no trace of a fourth inner angle. Save for its ~ - ¢~ ° . •

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.

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e.b. • ~. ~. ~v.~ *.,~ ~" ~ ~.. ~ ~. Zygomatic breadth.

¢¢ ~ ¢¢ ¢~ ¢z ~¢ ~ ¢z ¢0 ¢~ Interorbital constriction. ~t e,,

~, ~ ~~, ~ ~ t~ ~ ~ ~ Mastoid breadth. ob ob ob t:: ~ ob c~ &~5~

"q~ &~ &c~ ~c~c~ &~ Q~ ~ &w ~ Occipital depth (median).

¢4 "~ "qt~ "q~b ~5~t~~ ~ -h°~ ~:t~'~ ~ Nasal length.

~ ~ ~ ~ ~ ~ oc -~ ~ Diastema.

f~ ~. ~ ~ c~ ~ c~ -q ~ ~. ~ Maxillary cheek-teeth ~- ~ ¢~ d~ .z~ ~ ~ w ~ ~ (alveolar)•

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t9~ "puvpoo~ 'soF~..*q~H aouul 9~t~ uw.,f sa2oA 368 Mr. T. D. A. Cockerell~JDeserlptions and smaller size the skull cannot be distinguished from that of M. a. neglecters ; it differs quite strikingly from the skull of mlal in its smaller siz% relatively greater zygomatlc breadth, broader brain-case, and longer basioceipital (17"3 °/o of condyle-basal length). For ttle cranial dimensions see table on p. 367. Remarks. This mouse is apparently a dwarfed insular development of M. a. neglectus, tile form inhabiting t}le Scottish mainland. The presence of such an animal on Muck is the more interesting when we recall that on Eigg, as on Skyc, Mull, Jura, Islay, Gigha, and Arran the grass- mice are either identical with exsul or more nearly related to it than to neglectus. It seems probable that Eigg and Muck have been separated from each other for a very long time and that Muck has been joined with the mainland at a more recent dale than that of the severance of most of the other islands.

XLIIL--Descriptions and Records of Bees.--LIV. By T. D. A. COCKERELL,University of Colorado.

Megachile vincta, Vacbal. Two females from Guayaquil, Ecuador (Buchwald; Alfken coll. 1). Previously known only from Arica, Chili. In one the abdomen shows distinct green tints. The ventral scopa is clear white, with a little black hair at extreme apex.

Megachile pyrrhogastra, sp. n. .--Length about 12~ ram. Robust ; head and thorax black, with long pale ochreous hair; abdomen bright ferruginous, the first segment above with ochreous hair, second to fifth with rather broad, entire, orange-fulvous hair-bands; ventral scopa white, scanty and fulvous on last segment ; extreme sides of third and following segments with black hair, long and conspicuous, invading the scopa, on the fourth. ~'ings strongly reddish, with an orange tint. Legs black, the femora more or less stained with red. Mandibles broad, quadridentate ; clypeus shining, strongly punctured, the lower margin with two tubercles close together ; antennm chestnut-red, dnsky above; meso- thorax granular from very dense minute punctures ; tegulm