146 Prof. C. Chilton on 



XV. — Xote on the Croh ITynioiio.'soina depressnm, Jncquiuot 

 and Lucas. By ClIAULKS ClIILTON, M.A., D.Sc, F.L.S., 

 PiotV.^sor of Biology, Canterbury College, New Zealand. 



[Plate \.] 



TnK little ciab lli/menosoma depressumySAC(\\\\\\oi and Lucas, 

 was described many years ago*, but does not: appear to have 

 been recognized since, and sonic confusion and doubt lias 

 tliert fore arisen with regard to it. As I ]in]>pen to have seen 

 some sjiccimons which, in my opinion, undoubtedly belong; to 

 the s|)ecies intended by Jacquinot and Lucas, it is only just 

 to their memory that I should endeavour to establish the 

 validity of the species in question ; at the same time I can 

 add one or two facts which are, ])crh;\p3, not without interest. 



AVhite, in ISlfi, established llalicarc'inus as a subgenus of 

 Iljimenosoma, and the second of the two species placed under 

 it by him was llymenosoma depressum, Jacquinot, a species 

 which was transferred to Ilymeuicus by Dana in 1852. 

 According to Miers, however, the specimens referred to 

 Jacquinot's species by White were distinct from it, and he, in 

 1876, named them Elamena Wliitei^. Miers had not seen 

 any specimens really referable to Uymenosoma depressuntj 

 Jacquinot and Lucas, and in the ' Catalogue of the N. Z. 

 (Jrustacea,' p. 51, gives this species under the name 

 '^ J/>/nienicus depressus?," quoting Jacquinot and Lucas's 

 description, and adding: — 



" The carapace is represented as nearly circular, the front 

 very narrow, not longer than the eyes, and of eqiuil width 

 throughout, ^i'here is apj^arently a small tooth outside the 

 eyes. Third joint of the external maxillij)eds much the 

 largest. I have not seen specimens of this species." 



Here the story of this species appears to end so far as 

 printed records are concerned. The new facts that I am 

 able to add are as follows: — 



In Ai)ril 1888, in the collection of ^Ir. R. Helms, of 

 Greymoulh, w hich was submitted to me for examination, I 

 found a dried crab which, by its yellow colour, flat depressed 

 carapace, and long legs evidently belonged to the species 

 described and figured by Jacquinot and Lucas. In 1893, 

 in the collection of the late Mr. S. II. Drew, of Wangaimi, I 

 found t\\o specimens of the same kind which were labelled as 



♦ Vuv. Pole Sud, Zfol. iii. Cnistac^?.^ p. 02, pi. v. fi-s. .34-39. 

 t See" Stebbing, P. Z. fcJ. 1900, p. o22. 



