180 Bulletin, Vanderbilt Marine Museum, Vol. Ill 



posed of a series of about ten forward-directed teeth, seven of which 

 are anterior to the deep cervical groove. The antennal spine is sharp, 

 upward-directed and well developed; the pterygostomian spine is 

 longer and points downward and forward, is very acuminate and lat- 

 erally'' compressed, while the hepatic spine is the most prominent of 

 the three. Of the thirteen specimens before me, ten have the hepatic 

 spine as shown in the figure, while the remaining three have this spine 

 wider, as shown in the photograph. The average hepatic spine is wide, 

 laminate proximally, flaring outward with an acuminate apex. The 

 upper lateral carinae are denticulate anterior to the cervical groove, 

 but posterior to it form a single long ridge. The median lateral 

 carinae consist of a conspicuous, laminate ridge, which terminates an- 

 teriorly just behind the clear-cut cervical fossa, in a small, sharp 

 tooth which is in line with the big hepatic tooth. The lower lateral 

 carinae are also unbroken except by the cervical fossa. The hepatic 

 suture is deep, uniting with the cervical groove anteriorly. 



The first abdominal segment is ornamented with three sharp, for- 

 ward-directed spines, one in the median dorsal line and one on each 

 side, in line with the upper lateral carina. The second to sixth seg- 

 ments, inclusive, each bear in the median dorsal line, two laminate 

 teeth, one behind the other, and separated from each other by the 

 decidedly transverse groove ornamenting the respective segments. 

 This dorsal carina is very pronounced and terminates posteriorly in a 

 pointed tooth projecting above the telson. The remaining surface of 

 the abdomen is very coarsely tuberculate. The epimeral margin of the 

 first segment has one tooth ; of the second to fifth segments, inclusive, 

 each segment has two sharp teeth, the hinder tooth of the fifth epimera 

 being quite sharp and flaring as is also the only tooth of the sixth 

 segment. The telson is very acuminate, with the tip upcurved ; there 

 is a distinct median dorsal groove margined by a carina, which in turn 

 is separated by another groove from the carinate lateral margin. The 

 rhipidura is composed of a very small peduncle and the blades are 

 not quite as long as the telson, the inner blade narrow, unequally 

 ovate, quite tapering distally, the outer blade more widely oval dis- 

 tally; both with ciliated margins. 



The eyes are large, globular. 



The antennulae are nearly as long as the carapace, biflagellate, the 

 outer branch being conspicuously thicker than the inner. 



The antennae have a scaphocerite which is oar-blade shaped, about 



