Wkight — Limnesthcria : A Netv Conchostracan Genus. 199 



The Limbs of the Trunlc. — The delicate foliaecoiis ajipcndages, the 

 branchial feet, cannot liu studioil, as they only nccm' as very nmcli crushed 

 impressions, thougli three of Hk^ih were indicated on specimen 13, fig. oB. 

 I'lUt the strongly ehitinizeil i-lasper, into whifh tlirco segments of the first 

 trunk-limb have been modilied in the male, is well adapted for preservation, 

 and has been studied in three of these specimens. 



First pair of Trunk-Zimbs (Claspers) in Male (Plate XXIV). — In all the 

 material examined, six specimens were males, showing these highly modified 

 trunk-limbs. There were never more than two claws found ; therefore, it may- 

 be asserted with confidence that, as in the genera Limnetis and Cyclestheria, 

 only the first pair of tvunk-limbs are liiodified as clasping organs. This 

 " hand " or clasper is formed by the three last segments (4th, 5th, & 6th) of 

 the normal trunk-limb. The 4th segment fb.) is broad, sub-triangular in 

 shape, and is projected on its inner margin into a rounded lobe, which 

 carries two rows of strong setae — the " comb " (c). The thumb-like movable 

 process which in living genera usually arises from the distal end of this joint 

 (Plate XXIV, figs. 3 and 4, p.) was not seen on specimen 1, but is represented 

 in specimen 2 by a small triangular, setiferous appendage (Plate XXIV, 

 fig. 2b, p.). The 5th segment is a strong curved claw (cl.), bearing at its tip 

 nine small setae, which probably represent the basal portions of long, slender 

 bristles, similar to those borne in this position by the claw of Cyclestheria 

 hislopi. One long bristle occurs near the tip of the claw, and a row of 

 seven small setae near its base. The last or 6th segment — the " forefinger " 

 (f.) — has the form of a slender appendage and shows no ti'ace of setae. 



The remarkable similarity of the clasper of Limneslheria ardra to that of 

 Estheria is seen by comparing Plate XXIV, fig. 5, with figs. .3 and 4, which 

 represent the claspers of two species figured by Packard. 



The Telson (Plate XXIV, fig. la).— The telson or tail is the last abdominal 

 segment. It consists of a broad, somewhat compressed plate (pi.) of 

 approximately rectangular form, bearing terminally two claw-like appen- 

 dages — the caudal furcae (c.f.). The ventral edge is smooth, gently curved 

 and prolonged posteri<irly into two curved denticles (d.;. The dorsal edge is 

 produced into two lamellae (1.), each bearing a row of small bristles, the 

 terminations of which have not been preserved in this specimen, but which 

 may be presumed to have existed (see Plate XXV, figs. 5 and 6). Each 

 lamella terminates in a stout, strongly recurved spine — the caiulal spine — 

 (c.sp.). Alauy tclsons were preserved, and, besides that of the type-specimen 

 on Plate XXIV, those of five other specimens are sketclicd on Plate XXV 

 figs. 2a, ."., a, 6, 7). 



The es,scntial structure of all these telsoiis is the same, but they diller 



