122 Bulletin, Vanderhilt Marine Museum, Vol. Ill 



almost the posterior margin. The second transverse groove is the 

 urogastric, which is situated two-fifths of the carapace length from 

 the hind margin ; it unites with a longitudinal groove, which parallels 

 the heavy carina on its upper side. There is also a lighter curved 

 carina not far above the lateral margin, not reaching to the posterior 

 margin, and curving upward anteriorly to unite with the long, longi- 

 tudinal groove. There is a short, curved groove extending from the 

 anterior margin of this carina, down to the lateral margin of the 

 carapace. The postlateral margins of the carapace are somewhat 

 produced, convex, overlapping the first abdominal segment; the 

 posterior margin of the carapace is relatively straight in the median 

 line. 



The carapace is 21 mm. long; the abdomen segments, one to six, 

 32 mm. long; the telson 8 mm. long. The first, second and third 

 abdominal segments are subequal in length, each 5 mm. long in the 

 median line; the fourth segment is 6 mm. long; the fifth segment is 

 5 mm. long and the sixth segment is 10 mm. long. The first five 

 segments have the posterior margin sinuate in the median and upper 

 lateral regions, on the median lateral region the margin is slightly 

 notched, beyond which the margin runs obliquely outward, uniting 

 with the convex lateral margin; this portion of each segment is thus 

 produced, overlapping the segment following. The first abdominal 

 segment has a transverse groove across the median region, just behind 

 the anterior margin, which then extends across the segment obliquely 

 to the notch on the lateral region of the posterior margin ; two other, 

 shorter, grooves unite with this and with each other circumscribing 

 a triangular area whose apex nearly reaches the triangular margin. 

 The lateral margin of the first segment is excavate in a straight line 

 above the basal joint of the leg, and convex and ciliated anteriorly 

 and posteriorly. The second abdominal segment has a short curved 

 groove extending backward from the notch on the posterior margin 

 of the first segment, almost to the middle of the second segment. 

 There is a narrower subtriangulate figure outlined on the lateral part 

 of this segment, its upper angle reaching to the notch on the posterior 

 margin of the second segment ; another short, forward-directed groove 

 runs from this apex a third of the length of the segment across it; 

 the lateral margin of the second segment is excavate anteriorly and 

 very convex on the posterior half. The third segment is similarly 

 ornamented laterally and margined as the second ; the fourth seg- 

 ment is similar to the third, except that the convex hinder half of its 



