148 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



The dorsal surface of the carapace of swetti is smooth and shining. 

 The cervical groove does not cross the median area, although it does 

 interrupt the gastric groove. There are no carinae on the carapace 

 except for the reflexed portions of the marginal carinae, visible in the 

 posterior quarter of the carapace, and vi^ithin the area bounded by the 

 marginal carina and its reflexed portion there is on either side a faint 

 trace or suggestion of a short bit of what may be taken to represent a 

 posterior remnant of a lateral carina, scarcely more than an angulation 

 in the surface of the carapace that interrupts the reflected light. Just 

 before the mid-point of the posterior margin of the carapace is a small 

 raised ring with 2 posterior oblique, laterally directed rays. 



The corneae are obliquely placed on their stalks; their long axis is 

 slightly longer than the median axis of the stalk and the thickness of the 

 cornea taken together. The thickness or perpendicular height of the 

 cornea is about Yo the median height of the stalk exclusive of the cornea. 



The outer inferior angle of the merus of the raptorial leg is rounded ; 

 the carpus has a groove and keel above, the latter entire and terminating 

 anteriorly in a rounded-off right angle; the propodus is armed with the 

 usual 3 spines and series of pectinations; the dactylus is armed with 4 

 teeth, including the terminal one, in this respect like S. miles and unlike 

 S. fasciata, which has 5 teeth. The outer margin of the dactyl in our 

 species is angled posteriorly and notched just before the angulation. This 

 is also the case in S. fallax, but not in S. fasciata. 



The free thoracic somites are smooth and with carinae on the 6th, 

 7th, and 8th somites only in line with the intermediates of the abdomen 

 other than the marginals; the 5th somite has a pair of curved carinae 

 almost meeting on the median line anteriorly; lateral processes of this 

 somite consist of 2 low, more or less anteriorly-posteriorly flattened lobes, 

 the upper is somewhat obliquely bent forward and is more prominent 

 on the right than the left side, below on either side of the somite is a 

 ventral spine; lateral margins of the 6th and 7th somites broadly rounded, 

 forming somewhat auriculiform lobes. 



No submedian carinae on the abdominal somites except the 6th; 

 intermediate, lateral, and marginal present on all; intermediates and 

 laterals spined on 5th and 6th, marginals spined on 4th and 5th only. 



The median carina of the telson is well marked and ends in a promi- 

 nent spine; it is more or less paralleled either side by 6 thinner carinae 

 (not counting marginal) of various lengths and curvatures; the first 

 pair lie a little within an imaginary line continuing the carinae which 



