592 Crustacea observed during the Cruise of H. M.S. e Challenger' 



got in depths of 1950, 1800, 2150, and 2600 fathoms. In the second of 

 these hauls we found a rhizocephalous cirriped in the open breeding-pouch 

 of a very large Hymenaster, which is about to be described by Professor 

 Wyville Thomson. Such crustaceans have, however, as far as I can see, 

 never been described from an echinoderm; and I am not quite sure 

 whether the specimen in question had not been detached from one of the 

 shrimps which came up at the same time and tumbled into the open pouch 

 of the Hymenaster. Another Cirriped, a Scaljpellum, was caught in the 

 last dredging (2600 fathoms), showing once more that Cirripeds are 

 among those Arthropods which may be met with in very great depths. Of 

 Isopods there were specimens of the described Munopsid, and fragments 

 of another hitherto unknown member of this tribe. 



The Schizopods yielded again several very interesting forms. Petalo- 

 phthalmus inermis came up from 1950 fathoms, and from the same place 

 we got the posterior part of a cast Gnathojphausia skin. This genus, three 

 species of which have been described by me from the depths of the 

 Atlantic, is allied to Lophog aster, but distinguished by its carapace being 

 not attached to the five posterior segments of the pereion, and by acces- 

 sory eyes on the second maxilla. It is difficult to tell from this frag- 

 ment whether it belongs to one of the described species : in size it seems 

 to me to have been intermediate between G. gigas and G. zoea. The 

 Euphausiidse are also represented by a very interesting new form, a large 

 species of Thysanopoda (from 1800 fathoms), a genus which has hitherto 

 not been found in deep water. It has a length of 50 millims., and is, 

 like the deep-sea Eiophausia which I have described in my preceding 

 paper, perfectly untransparent. I am not able to say how many pairs of 

 accessory eyes there are in this species, but I think that they exist, and 

 that black spots between the first pleopods may turn out to be such organs 

 of sense. 



Of Chcdaraspis there was a specimen of the species which I have men- 

 tioned already (C. unguifer), and another very remarkable form which I 

 shall call C. cdata. In this one the large carapace is very thin and soft, 

 perfectly loose, and covers three of the abdominal segments. The last 

 legs are not elongated like in C. unguifer, but somewhat shorter; the first 

 of them somewhat enlarged and recurved in its first joints. 



Among the higher Decapods there were two species of Gcdathea and 

 some Peneid and Caridid shrimps, which are not particularly interesting. 



