Wi;if:itT — Liiiincsthcrla : ,1 New Conclmatracan Genus. 195 



111. — JjlJlNADHl.LA : 



(1) Cypridoid shell, i.e., flattened alonj; the vuntnil iiiai-gin. 



(•2) Head fui'iiishod witli one eye only. 



(,3 & 1) Auteunae .sub-equal, and joints provided with numerous spines. 



(5) Twenty-four pairs of trunk-limbs. 



(C) In males two anterior pairs of trnnlc-limbs are modified as claspiiij,' organs. 



(7) Large telson. 



ItciiKirka. — This genus differs from Liumadia in having its antennae almost 

 equal, while it differs from Estheria in the fact that the antennal segments bear 

 numerous spines, while in Estheria those segments have only one spine each. 



IV. ESTHEIUA : 



(1) Shell oval, more or less globose, with 18-22 lines of growth. 



(2) Head very large. No halt-organ, 



(3) First antenna or antennule remarkably long and jointed. 



(1) Second antenna with a stout, multiarticulate scape, and sub-equal flagcllae, 



which extend well beyond the edge of the shell ; 15-20 antennal joints. 

 (5) About 20 pairs of trunk-limbs. 



(Gj In males two anterior pairs of Lruuk-limbs arc modified as clasping organs. 

 (7) Telson with finely dentated caudal lamellae and claw-like furcae. 



v.— Cyclestheria : 



(1) Shell cyclas-like, inequilateral, with few lines of growth. 



(2) Only one eye. No haft-organ. 



(3) First antenna or antennule simple, cylindrical. 



(1) Second antenna rather stout with strong recurved spines along the upper 



branch and part of the scape. 

 (5) Sixteen pairs of legs. 



(0) In male only first pair of trunk-limbs modified as clasping organs. 



(7) Caudal plate short and broad, with two slender mobile claws at lip, with 

 great development of very strong and unguiform dorsal spines. 



VI.-— LiMNADOPSIS : 



(1) Shell ovate, compressed, very thin, 25 mm. long, being very large for the 



Conchostraca. Union between the two valves extending all along the 

 dorsal line, which is raised into a much-compressed, spined keel. Lines 

 of growth well marked. 



(2) Haft-organ present. 



(3) First antenna or antennule small. 



(4) Second antenna stout, multiarticulate. 



liemarkx. — Limnadopsis is Estheriau in character, but distinguished from 

 Estheria by the presence of a haft-organ, and from Limnadia and the other 

 Limnadiidae by the spinous processes on the carapace. 



VII. — Leptesthekia : 



(1) Shell much compressed, oblong in form, with the umbones very small and 

 placed far in front, dorsal edge straight, ventral slightly curved, both 

 extremities rounded. Valves thin, pellucid, with the lines of growth 



rather slight, not I'idge-like. 



