28 DR. R. V. WILLEMOES-SUHM ON SOME ATLANTIC 



element in Nebalia. We have now, however, discovered another Schizopod, in which the 

 legs are entirely normal and the shield is phyllopodal {Gnathophausia), hut evidently 

 not to he derived from the Esther ia-like shell of Nebalia, but from the carapace of Apus. 

 And in this same Gnathophausia there is an abdominal segment which shows that, now 

 being essentially a Schizopod, it is in genealogical connexion with forms which have had 

 more segments in the abdomen than the Schizopods have. 



These two forms, though both Schizopods, show characters which connect the lower 

 Crustacea more and more with the higher ones. Perhaps the fossil forms might give some 

 further evidence. We may also hope to get more forms from the deep sea which will 

 enable us more and more to understand the curious genera which are known under the 

 names of Ceratiocaris, Dithyrocaris, &c. 



IV. On some Genera op Schizopods with a feee Dorsal Shield. 

 1. On Gnathophausia, a new Genus o/'Lophogastridse. (Plates IX. & X. figs. 2-4.) 

 During our cruise from the Bermudas to the Azores, Madeira, Cape-Verds, and from 

 there to the Brazilian coast, three species of this new genus of Schizopods came up in 

 the trawl or in the dredge. One of these species (now probably figured in Professor 

 Thomson's " Notes from the 'Challenger,' " in 'Nature') is very large, probably the largest 

 Schizopod which we know. Of this one, which I have called Gn. gigas, only one male 

 was caught ; of another, smaller species, Gn. zoea, two males and two females ; and of the 

 third, Gn. gracilis, only one male. Of these I have dissected one female of Gn. zoea. I 

 have also made drawings of the legs of Gn. gigas, which I could not dissect ; but finding 

 that they have a close resemblance to those of the former one, I shall not publish them. 

 A sketch of the oral apparatus, however, and of a maxilliped, of the larger species are 

 among my figures. 



Gnathophausia*, n. gen. 

 1. Gnathophausia gigas, n. sp. 



The specimen, a male, came up from a depth of 2200 fathoms in lat. 38° 22' N. and 

 long. 37° 21' W., between the Bermudas and the Azores. 



It has a length of 142 millims., and much resembles at first sight a large Caridid 

 shrimp ; but the abdomen is straight and not bent down by the enlargement of the third 

 pleon-segment, as is the case in the Carididse. 



■ The Carapace. — Its anterior part extends as a triangular rostrum (35 millims. in 

 length), starting in the form of a high ridge from the midst of the hepatic region. Prom 

 its base to the top of the rostrum the dorsal shield has a length of 64 millims. ; it is a 

 flexible parchment-like duplicature of the skin, covering entirely the lateral branchiae, 

 and touching with two lateral and backward-directed spines the middle of the second 

 abdominal ring. Its upper posterior edges, however, do not quite cover the last segment 

 of the pereion. In Lophogaster it leaves two segments entirely free, and its borders are 

 not united with the pereion. Here the carapace starts from the cephalic and the firs.t 

 pereion segments as in Apus and Nebalia. It is in no connexion with the five posterior 



* JTVaflos and tyaiiaios. 



