200 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



The telson is a little more than twice as wide as long. Its dorsal sur- 

 face is bluntly and obscurely carinated, showing 9 low ridges in groups of 

 3 ; a median group of 3 forming a flat subtriangular area, with a more 

 laterally disposed group of 3 either side. The carinae of each group are 

 provided each with a sharp posterior spine of which the longest and most 

 prominent terminates the median carina of the telson ; the first, or inner- 

 most, low broad carina of the right lateral group of three is itself broad 

 and low and posteriorly trispinose; it is separated either side from the 

 adjacent spines of this transverse series of spines on the dorsum of the 

 telson by a shallow groove or depression, as are, on either side of the tel- 

 son, the 2 outermost spines from each other by an even less well-marked 

 and shorter groove. The lateral margin of the telson is a bit thickened and 

 entire, ending posteriorly in a stout lateral tooth*'''^ or spine; one spiniform 

 denticle removed from the lateral tooth is a stout intermediate tooth or 

 spine, the largest and longest of the marginal teeth or spines ; one denticle 

 more and there is another spine or tooth several times larger and stouter 

 than the spinous denticle immediately preceding; next in order on the 

 posterior margin, moving toward the median line, are 2 more teeth or 

 denticles, of which the more medially placed one is just external to the 

 long, slender, movable submedian spine; on the inner side of the sub- 

 median spine is another spine or denticle, one of 9 arming the left moiety 

 of the median notch, on the right side the corresponding spine is one of 8. 

 Above and to the inside of the base of each submedian spine is a tuberculi- 

 form swelling, canying 2 little tuberclelike teeth or projections; the 

 outermost of these tuberclelike teeth is the larger in each case and is itself 

 more or less bidentate. Beneath, the telson is unarmed. 



The bifurcate basal process of the uropods is formed of 2 stout, flat- 

 tened spines, of which the inner is the thicker, being dorsally keeled along 

 its inner margin ; it exceeds the outer spine by nearly % of its own length. 

 The outer margin of the basal segment of the exopod is furnished with 6 

 movable spines ; the upper surface of the peduncular segment is flattened 

 and carinated along its anterior or outer edge, as well as its posterior or 

 inner edge of this flattened upper surface; the posterior carina ends dis- 

 tally in a short, subacute, possibly acute spine. 



Color: Black markings disposed much as indicated in the accom- 

 panying figure. 



67 According to Kemp's most useful and convenient system of nomenclature, 

 adhered to in this paper in most instances. 



