206 Bulletin VanderbUt Marine Museum, Vol. VII 



The fourth somite is nearly twice as long as the third, and 

 has the extreme postlateral angle produced into an elongate, 

 acuminate, triangulate process, bent outward; anteriorly this 

 lateral margin is sinuate, forming a rounded process slightly 

 in advance of the median area. 



The fifth somite is subequal in length to the fourth, the cari- 

 nate lateral margin is sinuate, with a reduced lobe medially and 

 the postlateral angle forming a slightly larger, acuminate, tri- 

 angulate tooth. 



The sixth thoracic somite bears the typical Squilla^ rounded, 

 anterolateral process which overlaps the bases of the last pair 

 of legs and which process is dorsally carinate. 



Except for this flaplike process on the first somite, the first 

 five abdominal somites are similar, nearly subequal, in length, 

 with the lateral margins carinate and produced at the postlateral 

 angle into an acute, small spine, which is about 1.5 millimeters 

 long. The sixth abdominal somite is a trifle shorter than the 

 fifth, with the lateral margin oblique, above the base of the 

 uropoda and bearing in addition to those carinae common to all 

 the abdominal somites, a submedian pair of thicker, longitudinal 

 ridges, which arise shortly behind the anterior margin of the 

 somite and each terminates posteriorly in an acuminate tooth, 

 which projects, one on either side of the median carina of the 

 telson. In addition to the carinate lateral margins, there are 

 two pairs of lateral carinae, the upper of which occur about 

 halfway between the median dorsal line and lateral margin, 

 originating on the hinder portion of the third thoracic somite 

 and being similarly present on the postlateral three-fourths of 

 each of the remaining thoracic somites, terminating bluntly 

 on their respective posterior margins, while on the abdominal 

 somites this carina begins in each instance slightly behind the 

 anterior margin and terminates in a small spine projecting be- 

 yond the posterior margin of the first four abdominal somites, 

 while on the fifth somite, this spine occurs slightly in advance 

 of the posterior margin and on the sixth somite, the carina is 

 sinuated anteriorly and interrupted briefly, while posteriorly the 

 terminal spine occurs in advance of the hinder margin. The 

 second lateral carina is located midway between the upper carina 

 and lower lateral margin and originates on the rounded antero- 

 lateral process of the first thoracic somite, just behind the ante- 



