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



Section 1. — Infero-posterior corners of carapace produced into sharp points more or less 

 elongated. Dorsal spine short or obsolete. Dorsal keel of carapace interrupted in the 

 middle part. Supra-orbital spines small or obsolete. Antennal scale small, not jointed, 

 outer margin serrate. Maxillipeds with a small exopodite. Epimeral spines of the last 

 caudal segment confluent on the ventral face, forming together a cordiform concave plate, 

 incised at the apex. 



3. Grnathophausia ingens (Dohrn) (PL II.). 



Lophogaster ingens, Dohrn, Untersuchungen iiber Bau und Entwickeliiiig der Arthropoden, 

 Zeitschr. f. wiss. Zool, Bd. xx. p. 610, pi. xx si figs. 12-14, 1870. 



Gnatlwphausia injfata, Suhm, MS. 



Gnathophausia ingens, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, 

 No. 3. 



Specific Characters. — Form of body rather robust, the anterior division (in the female) 

 greatly inflated. Carapace large, with the infero-posterior corners produced into small 

 slightly curved spines. Dorsal spine very short, almost obsolete. Eostrum short, very 

 broad at the base, indistinctly denticulate. Supra-orbital spines wanting; antennal spines 

 small but distinct; branchiostegal spines obsolete. Eyes with rather long and narrow 

 pedicles, cornea somewhat expanded. Antennal scale very small, subovate, apex truncate, 

 outer edge minutely serrate in the distal half Caudal segments distinctly sculptured, 

 both lappets of the epimera pointed. Epimeral plate of last segment large and deeply 

 •cleft at apex. Telson much longer than uropods; its lateral edges evenly arched. 

 Length, 157 mm. 



Remarks. — The present gigantic Schizopod had already laeen described and figured 

 by Professor A. Dohrn in the year 1870 from a somewhat defective specimen sent him from 

 the Zoological Museum of Hamburg. Notwithstanding that all the legs in his specimen 

 had been broken, Professor Dohrn was yet able to recognise it as a true Schizopod, most 

 nearly approximating to Lopliogaster ; and he described it as a new species of the genus 

 under the name of Lophogaster ingens. The examination of the specimen procured by 

 the Challenger Expedition, which is comparatively well preserved, fully confii-ms this view, 

 so far as regards the Schizopod nature of this form and its relationship to Lophogaster. 

 On the other hand, it cannot at present be strictly referred to the last mentioned genus, 

 but is to be regarded as a true Gnathophausia. This view was also suggested by the 

 late Dr. v. Willemoes-Suhm, who, in his manuscript notes, has mentioned this form 

 under the name of Gnathophausia injiata, n. sp. The specific denomination ''ingens" 

 proposed by Dohrn having, however, been given prior to the Challenger Expedition, 

 must of course be retained for the species. 



Description. — The specimen obtained by the Challenger Expedition is a fuU-grown 



