; 56 On Australian Entomostracans. Woolnorth, and several islands in Bass's Straits. The alter- ations of level at Point Nepean, Port Phillip, have already been observed and recorded by my able friend the late Dr. E. C. Hobson, in the 3rd vol. of the Tasmanian Journal. VIII. — On Australian Entomostracans. By the Eev. K. L. King, B.A. \Bead l%th July, 1854.] SUB-KINGDOM. ANMULOSA. Class Crustacea. Division Entomostraca. Legion I. Branchiopoda. (See " Papers and Proceedings," Vol. 2, Part II., January 1853. Legion II. Lophyropoda. LOPHYROPA. LaTREILLE. Lophyropoda. Leach, &c. Branchiopodis. Frange's (pars) Lamarck. Character.—Mouth furnished with organs fitted for masti- cation ; branchiae few, attached to the organs of the mouth body having an envelope (either in the form of a buckler inclosing head and thorax), or in the shape of a bivalve shell, inclosing the whole animal ; feet few in number articulations more or less cylindrical, and serving the ani- mal for the purpose of locomotion ; two pairs of antenna. — On Australian Entomostracans. 57 Order I. Ostracoda. OSTRACODA. LaTREILLE. Character.—Body enclosed entirely in a covering of two valves, resembling a bivalve shell; posterior jaws branchi- ferous; no external ovary; feet two and three pairs, adapted for progressive motion. This order contains three families, Cypridm, Cytlteridm, and Cypridiiiadce, I shall confine myself to the first of these. Fam. I. Cyprid^. Cypris. Muller et Auctorum. Character.—Two pairs of antennse ; superior, long with numerous joints, and a pencil of long filaments ; inferior, stout, and pediform. Feet, two pairs. * It would be unnecessary in this place to describe minutely the animals of this family ; such a description has already been, published in the Natural History of the British Entomostraca, one of the publications of the Ray Society, 1849, I need therefore but refer to that work, and add a very brief description, laying stress only on those particulars in which the Australian species appear to differ from the European. " The body of the animal is completely enclosed within a shell of two valves of a horny cretaceous substance, which :" in general appearance closely resembles a small mussel the body consists of two rounded portions of unequal size. The thoracic, from which spring the antennae, the antennules or rami, the organs of the mouth, and the first pair of feet and the abdominal, from which spring the second pair of feet and the tail, and which contains the generative system. * I have copied the above almost verbatim from Mr. Baird's work ; omitting only the notice of the eye, which the discovery of Newnhamia proves to be a generic, and not a family characteristic. H 58 On Australian Entomostracans. The eye is simple, no traces of crystallines having been discovered. It varies much in colour. It is generally single, but there are two eyes in Newnhamia. The superior antennae, consisting of seven articulations, which carry a pencil of long setee, and the inferior or the an- tennules (or as I shall henceforth call them the rami), composed of five joints, form together the principal organs of progression. Except in Candona, the rami carry a pencil of long seta3, springing from the extremity of the third joint,* and by means of these rami with the antennae, the little creature is able to swim through the water with con- siderable rapidity and steadiness. The mouth is situated on the inferior surface of the thoracic portion of the body, and consists of a lip, an inferior lip, a pair of palpiferous mandibles armed with strong teeth, and two pairs of foot jaws, both of which, at least in Australian species, carry a branchial plate fringed with long thick setee. There are two pairs of feet, the first of which is used in creeping on plants, or on the mud. These spring from the thoracic portion of the body, and are directed forwards, and terminated by along hook; the second pair are slender, directed backwards, and seem intended to support the ovaries ; the abdomen is terminated by a moveable bifid tail. I have been much interested in finding, in two instances, the reproductive organs largely developed; I believe they have not previously been met with, or at least described, in any of the Ostracoda. In Cypris carinata, and in Newnhamia fenestrata, the sexes are easily distinguished, and the males * Jlr. Baird calls this the fourth joint, from which the setae spring. But if this be the case, (which I will not venture to dispute, though I have not been able in that case to find the first joint), the Australian species must have six joints in each ramus. On Auslrulian Entomostracans. 59 are not uncommon, the generative system being nearly the same in both. I shall describe that of the former, although it was first discovered in the latter. The male organs consist of two testes, placed parallel to each other within the abdomen, and connected by a duct, each with its respective penis, PI. IX., A. 10, 0. 3. Each testis consists of a long narrow muscular cyhndrical vessel, surrounded by hairs arranged in pyramidal tufts, the whole being enclosed within a membranous covering, so as to form an oblong capsule. When the membrane is broken the testis assumes a curved shape, proving a considerable degree of muscular tension in its original condition. The penis, which is double and placed on the abdomen, is a pyriform organ, carrying at its extremity two short joints turning towards each other, and forming a clasping apparatus. The female parts are simple, PL IX., C. 4., being com- posed of two long pyriform (?) ovaries, each consisting of an envelope of tubular hairs enclosed within the abdomen. The only points of diflference peculiar to New?ihamia are, the testes are shorter and stouter, while the penes are altogether smaller. This, however, is counterbalanced by the shape assumed by the abdominal feet of the male, PI. IX., A. 11-12, which are evidently calculated for clasping. In Newnhamia coition takes place while the animals are swimming at the surface ; during the operation they sink towards the bottom. In Cypris carinata, on the contrary, the same operation is performed at the bottom or on the stem of a plant. Habits.—The Cypridse are certainly carnivorous. They are, in fact, the scavengers of the ponds in which they live. In the small basin in which I have kept several species for — ; 60 Oji Australian Entomostracafis, many months, under almost daily observation, I have fre- quently seen them attack other Entomostraca, such as Limnadia and Daphnia, almost before death ; and soon after death the shell has been found emptied of all its con- tents by these minute gourmands. A dead Limnea or Planorbis, or other small mollusk, is quite a dainty ; and hundreds may be seen heaped one upon another in a perfect turmoil of delight, each striving to get at the savoury morsel. '' Nee mora nee requies." And no alderman quits a civic feast with greater reluctance than these Cypridoe manifest when driven away from the sumptuous repast. This habit makes them of essential service in preventing the water from being corrupted by decaying animal matter as soon as a leaf or stalk begins to decay, it is covered with these little Crustacea. Yet I have doubted whether they attack it for its own sake, or for the sake of the animalculse which may be feeding on it, for they generally desert it before it has quite disappeared. This is not the case when they are feeding on dead animal matter. If we may judge from the shell of the genus Cythereis, (Jones), the genus Newnhamia supplies another link be- tween the marine and fresh water Entomostraca. Mr, Baird has discovered a fresh water Cythere in England ; and here in Australia we have an animal closely connected with the marine genus Cythereis. Both Newnhamia and Cythereis have two eyes, and a very tuberculose shell, and, indeed, the shell of the former is only separated from that of the latter by the flat plate at the ventral margin, by which it is enabled to cling to the surface of the water. I would therefore suggest the following as, in my opinion, a natural arrangement of the genera of the Ostracoda : On Australian Entomostracans. 61 3 Newnliamia ) rami 2 pairs] >- nata- 2 Cypris » tory having two of feet "" eyes and a 1 1 ^ Candona unable > to tubercular 3 pairs i 5 Cythere ) swim shell. of feet 1 4 Cythereis 6 Cypridina. —Two eyes and two pairs of feet. Appears to me to form a connecting link between the OsTKACODA and the Lynceid^e ; its peculiar terminal seg- ment of the abdomen, as well as its rami, being closely analogous with those of many of the Cladocera. *' There are three genera belonging to the family Cypridse in Australia. Cypris;— (Muller), rami provided with a pencil of long setse ; animal swimming, partly on its ventral edge ; eye single. — Candona; (Baird), rami destitute of the long setse ; amimal creeping on the ground or on plants ; eye single. Newnliamia ; —nov. gen., rami as in Cypris; animal swimming freely through the water on its back ; eyes two. Genus I. Cypris. 1. Cypris cari7iata, PI. IX. 0. 1-4. Shell nearly elliptical, but higher on the back ; the valves are unequal, the right being produced beyond the left at the * Professor M'Coy, in his late work on the " British Palseozoic Eock Sand Fossils,'' has expressed his opinion that " all the Cytherece of Palseozoic rocks are more properly Phyllopoda than Lophyropoda." I confess that the analogy of these fossils with the latter, through the recent species of Cythereis, appears to me to be almost established by the discovery of Newnliamia, 62 On Australian Entomostracans.