26 Bulletin, Vanderhilt Marine Museum, Vol. II 



of the fourth abdominal segment, as in the Indo-Pacific form. The 

 fifth abdominal segment is one and one-fourth times as long as the 

 fourth and has an acute tooth at its postlateral angle; the sixth seg- 

 ment is one-half as long as the fifth, and is ornamented with a sub- 

 median pair of acute, conical spines that form an elevation on the 

 surface of the segment and project beyond it for a distance equal to 

 half its length; a second pair of smaller, acute spines occur, one on 

 each side about haKway between the submedian and lateral margin 

 and about midway the length of the segment, not projecting beyond 

 its posterior margin. At the postlateral angle there is also an acute 

 conical spine which projects beyond the telson, between its margin 

 and the peduncle of the uropod. 



The telson is shield-shaped, sharply elevated in the median line into 

 a strong, laterally compressed keel which terminates subdistally in a 

 spine and has near it on either side a shorter, lower carina, outside 

 of which there is a second low carina, divergent and a trifle longer 

 than the inner one and terminating in a blunt tooth. Outside of this 

 carina the telson is depressed; there is a small, blunt node or tooth 

 proximaUy just inside the heavy carina which margins the lateral 

 border of the telson. There are a submedian pair of slender, acumi- 

 nate, articulated spines on the distal margin of the telson, with a 

 rounded, ridge-like elevation of the telson behind the base of each of 

 these spines, which are separated from each other by two small, 

 rounded nodes; outside the submedian spine the margin is excavate, 

 a low, broad, rounded node, followed on its outer side by an acute 

 spinule, then a long, acuminate, conical spine separated on its outer 

 margin by an excavation and a small spinule from another long, acute 

 conical spine, the outer margin of which is confluent with the lateral 

 margin of the telson. 



The uropoda have a strong peduncle that is marked on its upper 

 proximal surface by a carina terminating distally in an acute spine 

 with its tip incurved above the outer blade ; the produced part of the 

 peduncle is slightly longer than the basal section of the outer blade 

 and is forked distally, the outer angle terminating in a triangulate 

 scale which is only two-thirds as long as the similar spine which ter- 

 minates the inner angle; both of these spines are decidedly curved 

 inward; the inner blade of the uropod is long, narrow, oval, ciliate, 

 with a median groove proximally. The outer blade has the proximal 

 article as long as the inner blade, thickened with an approximately 

 median ridge, armed with nine acuminate, curved spines of succes- 



