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CRUSTACEANS they are here omitted for want of a recent opportunity for comparison.' l He explains that the English title of ' Opossum shrimps ' applied to Schizopods is due to their ' habit of carrying the eggs in a receptacle under the thorax until they are hatched, as in the analogous genus of Quadrupeds, the Opossum tribe.' This connexion of the eggs with the peraeon or thorax, instead of with the pleon or abdomen, is normal in the sessile-eyed Malacostraca. Cocks records M. spinulosus ' In ponds, Bar point, Gwyllyn-vase, Swan pool, Helford, Bream Bay, Pendower, St. Ives ; not uncommon.' Bate records the same species as M. chameleon, Bell having earlier identified it with Vaughan Thompson's M. chamaeleon. But these names of this very common species have to yield to the earlier Praunus flexuoms (O. F. Mailer). Concerning M. griffithnae, Bell, Bate remarks : 'We have taken this supposed species, but I feel assured that it is only the younger stage of a macrurous form, probably Palaemon or Crangon, the young of either genus of which it closely approximates.' 3 This hypothesis, however, must be dismissed as highly improbable, and at any rate it has hitherto met with no adherents. The species in question has rather been considered equivalent to Siriella armata (Milne-Edwards), and for this the correct name will be S. rostrata (Guerin) if Bell and Norman are right in supposing Guerin's figure to represent Milne-Edwards's species. 3 In 1856 R. Q. Couch described from Mount's Bay two species, Mysit oberon and Mysis lamornae* The latter of these is now referred to the genus Hemimysis (Sars), distinguished from Siriella by having the apex of the telson cleft instead of entire. The species is pellucid, but having the carapace bright red or orange, and some other parts flecked with the same colour. It is recorded from Falmouth also by Dr. Norman, who in his otherwise very complete revision of the British Schizopoda does not take notice of M. oberon. Couch describes this as having the rostrum bluntly triangular, reaching as far as the circumference of the cornea, the telson lanceolate, rounded at the apex, the rounded portion with two diverging teeth ; ' a perfectly transparent species, the large black eyes being the chief points by which it can be detected.' It must certainly, I think, be a Siriella, and but for the bluntness imputed to the rostrum might be regarded as anticipating S. jaltemis, Czerniavski. Norman records Macropsis dabberl (van Beneden) from Falmouth on the authority of Mr. G. C. Bourne. 6 This is a very interesting species, first described and figured by Slabber in 1769 as a shrimp with trumpet-like eyes, 6 but without any Latin designation. Like M. oberon it is pellucid as water, but the rostrum does not nearly reach the cornea of the exceedingly elongate eye-stalks. The telson is short, triangular, with rounded apex, and a tooth at each side where the rounding begins. It is rather singular that White, 7 who quotes from Couch's description of M. oberon, also mentions another translucent form as ' Mysis n. s, Plate IX, fig. 4, found, Falmouth (rock pools at), Rev. A. Norman, April, 1855.' Norman himself makes no reference to the brief description and undecipherable figure of this unnamed species. He on his own part reports that Neomysis vulgaris (Vaughan Thompson) is ' found all round our coast in brackish water at mouths of rivers, estuaries, salt marshes, and such-like places,' 8 so that we may safely add it to the fauna of Cornwall. Its genus is distinguished by a long subulate antennal scale and an elongate telson with entire pointed apex. In Schistomysis (Norman), the antennal scale is sub-rhomboidal, with the apex much produced beyond the lateral tooth. Two species of this genus, S. spiritus, Norman, 9 and S. arenosa (Sars) 10 are reported by Garstang from Whitsand Bay, and from the same locality Gastrosaccus sanctus (van Beneden). 11 Gastrosaccus being a preoccupied name, the last species must now be called Acanthocarh sancta. The Stomatopoda, as now restricted to the single family of the Squillidae, have the last three pairs of legs two-branched. In other respects they are very unlike the Schizopoda, with which they were for a long time rather absurdly combined. Couch mentions Squilla desmarestii, Risso, as rare, 12 and Bell adds S. mantis, Rondelet, 13 ending his description with the remask : ' Mr. Couch, to whom I am indebted for the specimen above referred to, informs me that the Squillae were brought from the distance of about a couple of leagues, where the bottom is rocky, with some spots of sand.' In this species the great prehensile claw formed by the second maxilliped has six teeth on the finger and the pleon has eight carinae or crests, while the smaller S. desmarestii has only five teeth on the clasping finger and its pleon is smooth along the middle of the back, being content on its first five 1 Fauna, pp. 80, 8 1. * 'Revision,' p. 40. 'Compare Norman, Ann. Nat. Hist. (1892), Ser. 6, vol. x, pp. 151, 263, and Guerin's Iconographit, Crustaces, PI. XXIII, fig. 2 ; Explication, pp. 1 6, 17 (the plate being earlier, the explanation later than 1837, the date of S. armata). 4 Zoologist, vol. xiv, pp. 5284, 5286. 5 Ann. Nat. Hist. (1892), Ser. 6, vol. x, 250. ' Naturkundige ferlustigingen, p. 136, PI. XV, figs. 3, 4. ' Pop. Hist. Brit. Crust, p. 145. * Ann. Nat. Hist. Ser. 6, vol. x, 262. ' Journ. Mar. Sin/. Assoc. (1891-92), vol. ii, N.S. 331. 10 Ibid. (1893-95), vol. iii, 221. " Ibid. vol. ii, 331. " Fauna, p. 8 i. B Brit. Stalk-eyed Crustacea, p. 353. I 2 73 35