SCLEROCEANGON ATROX. 133 



median carina of the carapace armed with three prominent, acute teeth ; 

 anteroJateral angles produced into large acute, wing-like processes ; behind 

 these, and on a line with them, the lateral carinas are armed with two teeth ; 

 there is a small sharp spine at the external angle of each orbit, and a small 

 pterygostomian spine lies below each of the antero-lateral wings. Median 

 dorsal carina of the abdomen well developed on the first to the fifth somites ; 

 the sixth somite and the telson are furnished with a pair of longitudinal 

 dorsal carinoe, which are armed with two pairs of spines on the telson, but are 

 unarmed on the sixth somite save a pair of minute spines at the posterior 

 end ; there is, besides, a less distinct lateral abdominal carina, which becomes 

 double on the fourth and fifth somites; the pleurte of the first abdominal 

 somite are unidentate, those of the second to the fifth bidentate; in old speci- 

 mens the pleural teeth tend to become obsolete. The telson ends in three 

 spinous teeth, the middle one the largest. The four posterior thoracic sterna 

 are armed each with an acute procurved spine ; these spines diminish in 

 length from before backward ; the abdominal sterna likewise are armed with 

 a median spine (second and third the largest) ; all of the sternal spines are 

 very much reduced in size in the full-grown female. The eyes are large 

 for the genus and are furnished with a small spine above the cornea. 

 Antennal scale broad, its internal margin convex. Legs as in S. ferox G. 0. 

 Sars. Outer lobe of the bilobed inner branch of second abdominal appendage 

 of male very short. 



Length of largest specimen (female), 162 mm. 



Station 3418. 660 fathoms. 3 males, 2 fem. (1 ovig.). 

 " 3424. 676 " 4 fem. 



The ovum measures 3.33 X 2.62 mm. 



In the number and arrangement of the gills this species agrees with 

 S. ferox, the branchial formula being : — 



The upper end of each gill is thrown forward, the lower end backward, 

 as in Crangon and other genera. The three pairs of maxillipeds are furnished 

 with well developed exopods, but there is no trace of this organ on the first 



