56 Bulletin Vanderbilt Marine Museum, Vol. VI 



squamae on the dorsal surface but there are only a few small ones 

 on the proximal portion of the fourth article. 



The abdomen consists of seven segments, of which the sixth 

 and seventh are usually reflexed, Galatheid-like. The first abdomi- 

 nal segm.ent is short and much narrower than the second segment, 

 fitting in the median posterior margin of the carapace and hav- 

 ing the lateral, or epimeral region, represented only by one short 

 spine at the postlateral angle. The dorsal surface of this segment 

 is covered anteriorly by about three rows of squamae, margined 

 posteriorly by a deep groove, which sets it apart from the rounded, 

 carinate and posteriorly setose, posterior margin of the segment 

 which bears at its extreme distal angle the lateral small tooth. 

 The second segment is the widest of the series, with the lateral 

 region produced into a strong, procurved spine, which has a small 

 tooth on the anterior side of the base of the larger one and on the 

 posterior side of the base there is a wide, ventrally directed, trun- 

 cate process; behind and above which, at the dorsal posterior 

 angle, is a small denticle. There is a strong, node-like, median 

 dorsal tooth with the apex directed forward ; a curved transverse 

 groove separates the more squamose anterior portion of the seg- 

 ment from the posterior portion. The third segment is like the 

 second but less wide, with a more acute, large lateral tooth which 

 differs in having no smaller tooth at its anterior base but does 

 have on the posterior side a ventrally directed tooth and behind 

 this a denticle ; there are two transverse grooves on this segment, 

 one setting apart the small anterior portion, which glides beneath 

 the preceding segment, and a second groove that extends from 

 opposite the median nodule to the posterior base of the large 

 epimeral tooth. The fourth segment is less wide, with a shorter 

 though strong lateral tooth, and with the median nodule greatly 

 reduced and directed posteriorly. The fifth segment is a trifle 

 longer in the median line than the fourth segment but less wide, 

 with only one stout, triangulate, lateral tooth and two transverse 

 grooves. The sixth segment is only two-thirds as long as the 

 fifth segment and much narrower, obliquely truncated laterally 

 above the base of the uropoda. The telson is almost twice as long 

 as the preceding segment, wider proximally than distally, with 

 the lateral and distal margins bluntly rounded ; the proximal third 

 of the telson is hard, finely squamose; the distal two-thirds is 

 softer, leathery, longitudinally striated; on the proximal two- 



