268 THE VOYAGE OF H.M.S. CHALLENGER. 



caudales postki ac in Dercothoe." He adds, " the genus is near Erichthonius (Edwards), if 

 not identical with it. The stress which is laid by Milne-Edwards on the rudimentary 

 character of the epimerals of the anterior thoracic segments, and his reference of his species 

 to the Coroishidae or gressorial Amphiijods, leads us to doubt the identity. The posterior 

 stylets have the same form as in Dercothoe, and the form of the head, the projectmg eyes, and 

 general habit, are nearly as in that genus. The approximation is so close, that the genera 

 are evidently of one and the same group; we have no evidence in the antennaj, caudal 

 stylets, or legs, that the species in every case are gressorial. The antennae are .slender, with 

 long flagella. The epimerals are broader than in some Gammari. The caudal stylets are 

 rather long." He also says that " a female PyctQus, bearing eggs, has been observed by the 

 author, which has the same form of hands as is characteristic of the group Erichthonius," 

 and that " in this genus as well as the preceding, the first joint of the legs of the fifth and 

 sixth pairs is very broad, while that of the seventh is narrow." 



Spence Bate makes Ericlithonius and Pydilus, and inclines to make Dercothoe, synonymous with 

 Cerapus, Say. Boeck puts them all three under that genus, which S. I. Smith has shown 

 to be distinct from them all. S. I. Smith unites Dercothoe and Pyctilus as synonyms of 

 Erichflionius, but still without noticing the breadth of the side-plates in (some at least of) 

 Dana's species, which, as Dana himself observes, makes the identification with Erichthonius 

 doubtful. In the work of Bate and Westwood, vol. i. p. 4-53, Dana is supposed to 

 have " founded his genus Pijctilus upon a misconception of the figure of Erichtlwniui> 

 difformis," but Dana clearly alludes not to the mistake in the figure, but to the express 

 words of the generic account, "I'^tat rudimentaire des pieces epim^riennes des premiers 

 anneaux du thorax," in the Hi.st. des Crust., vol. iii. p. 59. 



Dana's species are named Dercothoe emissitius, previously Gammarus emisdtius ; Dercothoe. 

 spectdans, previously " Amphithoe pecnlans (by mistake for S2}eculans)" ; Dercothoe? 

 hirsuticornis, previously Gammarus hirsidicornis ; Pyctihiit macrodaciijlus, previously 

 Erichthonius ? macrodactylug ; Pyctilus piigna.v, previously Erichthonius p)ucinax : Pyctilus 

 brasiliensis. 



In Family L Hyperidse, Subfam. 2. Hyperinte, contains Lestrigomis ferus ; Lestrigonus fuscns ; 

 Lestrigoniis rubescens ; Lestrigonus Fabreii ? Edwards; all which may perhaps belong to 

 the genus Hyperia ; the genus Metcecus, Kroyer, ought, Dana thinks, to be merged in 

 Hyperia, to which he assigns the species Hyperia agilis ; Hyperia trigona. The genus 

 Tauria is thus defined :■ — 



" Antennx quatuor breves, bad approximate, Imx crassiusculie. Pedes nuUi siibcheliformes nee 

 subpreh ensiles, 7mi vix abbreviati," with the type-species, Taiiria macrocepihala. 



The new genus CyUopiis is thus defined : — 



" Tauria; affinis. Pedes 7mi valde abbreviati. Antennx Imx et 2dx ad basin inter se remote," 

 with the tyjie-species Cyllopus magellanicus. 



Daira? debilis, Daira? depressa, Daira inxquipes, are at page 1596 transferred to the generic 

 name Dairilia (not Lairinia, as in the B. M. C. and elsewhere), Daira being preoccupied ; 

 but if Bovallius, 1885, is right in assigning Dana's species, not to Daira, Milne-Edwards, 

 but to Thamyris, Spence Bate, among the Lycajidae, the name Dairilia, Dana, will displace 

 Tlianiyris, by right of priority. The definition given liy Dana is as follows : — 



"Antenna' Imx non conspirux, 2dx exsertx. Pedes Imi 2dique plus mimisve p>relieimles : tarsi 

 pedum reliqnorum breves. Rami siylorum. caudalium longi." It is placed in the second 

 division of the subfamily, which have "Antennx totx breves. Caput oculique pergrajides." 



Subfam. 3. Synopinae, contains the single genus Syncqna, with the further definition, 

 " Frons subacutus. Antennx 4 longx, apeiix, Imx appendiculatx. Pedes 2 antici subcheli- 

 /ormes : piroximi duo vergiformes, quatuor sequentes subprehensiles, digito 2-artictdafo : 

 reliqui inediocrcs, unguiculati." Claus observes that this genus belongs to the Gammarina, 



