276 



THETIS SCIENTIFIC RESULTS. 



CERCEItS,^. Milne- Edwards. 



CERCEIS NASUTA, sp. nov. 



(Figs. 36a-&.) 



Stations 55, 57. 



Adult female — Body more than twice as long as broad, surface 

 covered with very minute reticulated ridges surmounted with 

 small scattered granules. Cephalon triangular in outline, with a 



median convex process, which des- 

 cends in front to between the bases 

 of the first antennae. The sides of 

 the head are inflexed inferiorly, and 

 gradually converge from the eyes 

 to the base of the descending fron- 

 tal lobe. First segment of the 

 paraeon about one-third shorter 

 than the length of the cephalon, 

 and almost equal to any two of the 

 six segments following. Pleon 

 equal in length to the peraeon 

 without the first segment ; the pen- 

 ultimate segment is well marked 

 from the telson, and bears faint 

 traces of the lines of coalescence; 

 laterally it is ornamented with two 

 broad transverse ridges, each of 

 which bears eight or nine smaller 

 longitudinal ridges, which are 

 studded with granules, the latter 

 increase in size as the ends of the 

 ridges are approached. Terminal 

 segment strongly convex, with 

 three ill-defined granular elevations, 

 the median one often with a rounded 

 notch ; sides converging to the 

 extremity, the latter exhibits a 

 small narrow incision, which is not visible from above. Side 

 plates of the peraeon sharply defined and strongly inflexed, the 

 first produced anteriorly to beyond the eyes ; the posterior lateral 

 angles of the first to the fourth are subacute with oblique borders; 

 fifth and sixth long, acute, and directed backwards ; the seventh 

 has the extremity rounded. 



Eyes small, situated at the posterolateral angles of tlie 

 cephalon. First antennte with the basal joints stout, the first 

 less than twice as long as broad, with the basal half swollen. 

 Second joint a little longer than broad, its length l)eing about 

 equal to the median diameter of the first ; third joint narrow and 



BODT VIEWED FROM ABOVE. 



Fig. 36a 



