98 Bulletin, Vanderbilt Marine Museum, Vol. Ill 



The carapace is short and very robust, with the cervical groove deep, 

 the hepatic groove distinct. The entire dorsal surface is covered with 

 sharp, forward-directed spines, which are arranged approximately in 

 longitudinal rows, the spines on the lateral region being smaller than 

 those of the anterior dorsal region. The abdomen, which is sharply 

 angulated at the union of the third and fourth segments, is moder- 

 ately robust, three times as long as the carapace, the first, second and 

 third segments covered with spines similar to those of the carapace, 

 except along the posterior margin of the third segment, where, in the . 

 median region, there is a small, embossed, tree-like figure composed 

 of five or six radiating, flattish squamae and on either side of which 

 there is a narrow bare band of carapace paralleling the posterior 

 margin of the segment, and anterior to this bare space on either side 

 is a patch composed of small spines. On the fourth segment the 

 anterior two-fifths of the median region is bare, this space continuing 

 laterally as far as on the preceding segment and also continued pos- 

 teriorly in the median dorsal line, where another longer embossed, 

 tree-like design is outlined by five radiating squamae, the top of the 

 tree design being directed posteriorly. On either side of the design 

 the posterior three-fifths of the segment is covered with small spines. 

 On the fifth segment there is a bare space and median tree design 

 directed posteriorly, similar to the one on the preceding segment. The 

 sixth segment is about twice as long as the fifth and is entirely covered 

 with sharp spines as on the carapace. The epimera of the first segment 

 is bifid, produced into two acute triangles tapering into spines ; those 

 of the second, third, fourth and fifth segments are tapered distally, not 

 exactly rounded, and each is armed distally with three spines placed 

 in a row, one at the anterior angle, one, median and one at the pos- 

 terior angle of the distal margin. There is an acute spine at the outer 

 postlateral angle of the sixth segment and a series of spines on the 

 ventral surface of this segment, which probably are of service in 

 enabling the animal to retain its grasp of the sea-fans, etc. The telson 

 comprises one-third of the length of the abdomen and bears two 

 longitudinal rows of large spines which converge distally, and be- 

 tween which there are two approximate rows of smaller spinules and 

 a median groove ; the tips of the telson are ornamented with a larger 

 pair of spines. The peduncle of the fan is small, spinose, the inner 

 blade ovate, narrowing distally and with a deep median keel margined 

 by two paired lines of spinules. The outer blade is wider with a sub- 

 distal spine at the outer angle, the distal margin broadly convex; 

 both blades have ciliated margins. 



