REPORT ON THE SCHIZOPODA. 17 



Genus 2. Ceratolepis, G. 0. Sars, 1883. 

 Ceratolepis, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda. 



Generic Characters. — -Carapace Highly indurated and very large, covering the whole 

 of the anterior division of the body, posteriorly abruptly truncate, not emarginate, 

 anteriorly forming a broad tridentate frontal plate, as in Lophogaster. Caudal segments 

 comparatively short and narrow, with small epimera ; the last not subdivided by any 

 transverse suture. Antennulae similar to those of Lophogaster. Antennal scale very 

 peculiar, forming a narrow flexuous plate of firm consistence, without any trace of 

 marginal bristles. Legs of comparatively more feeble structure than in Loiohogaster, 

 first pair modified so as to form gnathopoda, last pair (in female) without natatory 

 branches. Telson bifid, without distinctly articulated spines. Uropoda very small, the 

 terminal plates uniform, lanceolate and setose on both margins. 



Remarks. — This new genus is obviously rather closely related to Lophogaster, difier- 

 ing however, in addition to other characters, very distinctly in the form of the carapace, 

 the very remarkable structure of the antennal scale, the want of distinctly developed 

 exopods on the last pair of legs, and finally in the structure of the telson and uropoda. 

 The genus comprises at present but a single species, of which a solitary specimen only 

 was collected by the Expedition. 



2. Ceratolepis hamata, G. 0. Sars (PL I. figs. 8-17). 



Ceratolepis hamata, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 2. 



Specific Chojracters. — Form of body rather short and robust. Carapace slightly 

 nodulose above, with the dorsal area distinctly marked. Median tooth of the frontal plate 

 conically produced, and reaching to the end of the antennular peduncle, lateral teeth 

 much shorter and somewhat deflexed. Epimera of the caudal segments finely serrated on 

 the posterior margin. Last segment jutting out posteriorly into four rather large projec- 

 tions, two lateral and two terminal, the latter embracing the base of the telson. Eyes 

 rather small, almost wholly covered above by the frontal plate. Antennal scale con- 

 siderably projecting in front of the antennular peduncle, slightly curved outward 

 and somewhat dilated at the apex, forming there two acute angles, the one pointing- 

 forward, the other recurved in the shape of a hook ; internal margin angular in the 

 middle. Telson deeply cleft at the apex, terminal lobes acuminate and diverging. 

 Length, 12 mm. 



Remarks. — The species here treated of being the only one yet established in the genus 

 Ceratolepis, it is no easy matter to decide with certainty what characters should be 

 regarded as of specific significance. I have, however, sought in the above diagnosis to 

 adduce some few distinctive peculiarities, that may perhaps be of weight in this respect. 



(ZOOL. CHALL. EXP. — PART XXXVII. — 1885.) Oo 3 



