REPORT ON THE SCHIZOPODA. 39 



with a certain amount of hesitation, this form as a variety of Gnathophausia 

 zoea. In my opinion, however, it should decidedly be regarded as a distinct species, 

 although belonging to the same section of the genus as that species. From 

 Gnathophausia zoea (see PI. VI. figs. 6, 7) it may at a glance be distinguished 

 by the far inferior development of both the dorsal spine and the rostrum, by the 

 different form of the antennal scale, and finally by its much greater size. 



Description. — There are two specimens of this species in the collection ; one of 

 very considerable size, reaching a length of 136 mm. This is a female, with distinctly 

 developed incubatory lamellae. The other specimen is somewhat smaller, and would 

 seem to be a male, as no trace of incubatory lamellse can be discerned, but in other 

 respects it agrees perfectly with the first named specimen. 



The form of the body (see figs. 1, 2), as compared with that of the other species 

 belonging to this section, is rather robust, the anterior division being unusually massive 

 and thickset. 



The integuments are not very firm, though somewhat more so than in Gnathophausia 

 ingens and Gnathophausia gigas. 



The carapace is rather large, covering the whole of the trunk, none of the segments 

 of the latter being exposed. It is evenly arched above, and about as broad as high. 

 Both the lateral keels are distinctly marked, though by no means so prominent as in 

 Gnathophausia calcarata. The dorsal keel in this species does not experience any 

 interruption whatever, being continued along the whole back of the carapace, and running- 

 out posteriorly as a strong mucroniform projection — the dorsal spine. This spine, too, is 

 decidedly glabrous, and does not attain any considerable length, projecting but slightly 

 beyond the first caudal segment. As in the other sjoecies belonging to this section, the 

 infero-posterior corners of the carapace are evenly rounded ofi", without any trace of the 

 sjiine occurring here in the three preceding species. Moreover, the lower lateral keel, 

 which in these species runs out into the said spine, in this animal curves upward before 

 reaching the margin, and joins the upper one at the base of the dorsal spine. Close to 

 the posterior margin another elevated line may be seen, which, in connexion with the above 

 mentioned continuation of the lateral keel, rnarks off' a slight groove, running parallel 

 to the posterior edge of the carapace. The rostrum is exceedingly slender, and does not 

 seem to attain the length of the carapace. The point in both specimens, however, 

 having been broken off, its length cannot be stated with perfect accuracy. It is very 

 slightly curved, and exhibits in its distal part a few small denticles, arranged dorsally as well 

 as laterally, the proximal part being wholly unarmed. The supra-orbital spines are distinctly 

 marked off from the rostrum, jutting out as two very strong, anteriorly curving, and 

 acutely pointed, projections, to either side from the frontal part of the carapace, partly 

 covering the bases of the eyes above. The antennal spines, too, are rather well defined and 

 somewhat diverging. On the other hand, the branchiostegal spines are Cjuite absent. 



