18 Bulletin Vanderhilt Marine Museum, Vol. V 



rounded ; the lateral margins rather widely rounded at the postlateral 

 angle ; the posterior margin nearly straight. The visible thoracic and 

 first five abdominal segments have the lateral margins rounded but 

 those of each segment slightly different. The first five abdominal 

 segments are approximately subequal in length in the young speci- 

 men before me, with the lateral margins truncated ; the first abdominal 

 segment has a rounded pear-seed shaped, flap-like process at its antero- 

 lateral angle, projecting over the base of the last thoracic leg; and 

 the postlateral angle slightly rounded; the postlateral angles of the 

 second to fifth segments inclusive become slightly increasingly acute 

 from the first to fifth segments, but only the fifth segment has a 

 denticle like apex. The sixth segment is only one-half as long as the 

 fifth, and has a pair of acute, submedian spines that arise from the 

 posterior margin and in this young specimen these spines are two- 

 thirds as long as the sixth segment, forming an elevation on the sur- 

 face of the segment and projecting over the telson. A pair of short, 

 acute, median lateral spines occur one on each side midway the length 

 of the segment. The postlateral angle of the segment, above the base 

 of the uropod is produced into a strong spine which causes an eleva- 

 tion of the surface of the segment; the outer postlateral angle is 

 closely appressed to the base of the uropoda. 



The telson is shield-shape with a distinct median dorsal flat trian- 

 gulate carina, the median line of which is elevated in an erect carina ; 

 either side of this median carina, there is a flat triangulate carina, in 

 the median lateral region that terminates a short distance from the 

 posterior margin. The outer lateral margin is similarly carinate 

 except that the carina terminates in a small spine. The distal margin 

 of the telson bears a short, median, V-shaped sinus below the apex 

 of the median carina, on either side of which there is a blunt tooth, 

 tipped with a long, articulated, triangulate spine; on the outer side 

 of this spine at its base is a small triangulate spine, separated by a 

 linear incision from another smaller spine which occurs on the base 

 of the next large spine which is triangulate, acuminate, extending as 

 far backward as the front tip of the submedian tooth. Outside of this 

 tooth is the shorter, broad, triangulate tooth of the carinate lateral 

 margin, its apex in a line with the tip of the median lateral carina. 

 The base of the uropoda has a short median carina, terminating in a 

 spine on the upper surface above the base of the outer article; the 

 produced process is curved, distally unequally bifurcate; the outer 

 angle being an attenuated curved triangle that is slightly longer than 



