i 7 8 



CRUSTACEA MALACOSTRACA. III. 



antennular joint. - Mandibles (figs. 7 c and 7 d) with the part beyond the anterior condylus ninch 

 produced, long, rather slender and forming a pronounced and not very obtuse angle with the basal 

 half; movable lobe of left mandible well developed, slender, and before it a single seta; molar process 

 of both mandibles long, somewhat compressed and very slender, with the end acute and a few incisions 

 forming minute teeth on the distal half of its posterior margin. — Maxillulse (fig. 7 e) with the inner 

 lobe very short, reaching about to the middle of the outer lobe and feebly developed. Maxillae (fig. 7 f) 

 have the inner lobe small and, seen from below, covered by the inner branch of the outer lobe; the 

 inner lobe is subtriangular, and its narrow end has a couple of small setae; the two branches of the 

 outer lobe are broad, distally cut off with well developed setae on their terminal margin. — Maxillipeds 

 (fig. 7 g) very characteristic and similar in both sexes; second joint rather large and extremely broad; 

 lobe on fourth joint broad and low; fifth joint broad but a real lobe not developed, and sixth joint 

 without lobe; an epipod could not be discovered. 



Thorax with the epimera broad. — First pair of legs in both sexes with a large, oval, prehensile 

 hand (fig. 7 i); second pair in the female like the following pairs, but in the male (fig. 7 h) with a slender 

 and peculiarly shaped hand much smaller than in first pair; the other legs (fig. 7 1) are simple, slender, 

 with the claw somewhat short and thin and 110 auxiliary claw. 



The abdomen shows two short proximal segments immovably coalesced but well defined, and 

 the anterior possessing "epimeral" plates. L,ast segment triangular, with the end not incised or pro- 

 duced, and the lateral part of the wall not bent inwards on the ventral side. — Both rami of the three 

 anterior pairs of pleopods (PI. XV, figs. 1 a— 1 c) with marginal setae, and, besides, undivided excepting 

 the exopod of third pair, which has a well developed, oblique articulation; both rami of fourth and 

 fifth pairs (figs. 1 d and 1 e) undivided, branchial, and without vestige of transverse folding; endopod 

 of fourth pair terminating in a seta; exopod of fifth pair with the usual marginal or submarginal 

 protuberances or bosses feebly developed, without spines. Appendix masculina inserted at the base of 

 second endopod (fig. 1 b), distally very slender and frequently difficult to see, as in normal position it 

 is nearly hidden in a very pronounced furrow on the inner, much thickened margin of the endopod. 

 — Uropods with the sympod directed outwards and somewhat forwards; exopod very long, flattened, 

 somewhat narrow. 



The incubatory chamber is most peculiar; its major posterior part is formed by a single external 

 and exceedingly large pouch with a very broad aperture directed forwards, while the anterior part of the 

 chamber is formed by the marsupial lamellae, of which the three posterior pairs are well developed, 

 while the pair originating at first pair of legs are quite small; the whole ventral wall of the incubatory 

 chamber is very pellucid. 



Remarks. The main points of this description have been extracted from my former paper, 

 but many particulars, especially on the mouth-parts, have been added, and two corrections have been 

 made, viz. the existence of the molar process on the mandibles and of the appendix masculina (both 

 mentioned by Tattersall). 



Bathycopea Tatt. and Ancinella H. J. H. are synonyms, and both were established in papers 

 published in 1905, but Tattersall had the name without description published in Rep. Brit. Assoc. 

 Adv. Sc. 1904, and his name must be applied. He referred the genus to his new family Anciniidse, of 



