MUSEUM OF COMPARATIVE ZOOLOGY. 99 



mertis ; carpus short. Ambulatory legs (PI. IV. Fig. 2 a), well armed with 

 spines. 



First segment of pleon small, nearly concealed by the last thoracic segment, 

 and usually surpassed by the last pair of epimera, narrower than the three 

 following segments, which are slightly broader than the last thoracic seg- 

 ment without the epimera. Last segment broader than long, rounded and 

 ciliated behind, faintly furrowed on the median line posteriorly. Uropods 

 about equal to the telson ; basal segment more or less produced at the inter- 

 nal angle, outer ramus shorter than the inner, both rounded behind and 

 ciliated, denticvdated externally, with short spinules in the notches between 

 the teeth. 



The female specimens vary in length from 14 mm. to 25 mm. and in breadth 

 from 6 mm. to 10 mm., being mostly slightly broader in proportion than the 

 type specimen, which is 26.5 ram. long, 10 mm. broad. The large male in the 

 Blake Collection is 28 mm. long, 12 mm. broad ; the small female, 17.5 mm. 

 by 7 mm. A male collected by the U. S. Fish Commission at Station 871 is 

 22 mm. long, 9.5 mm. broad. 



The typical specimen of this species is destitute of color markings, which 

 may however have faded out from exposure to the light. Nearly all the other 

 specimens are rather distinctly marked, chiefly along the sides of the body, 

 with dark brown, arranged as follows. The lateral margins of the first thoracic 

 segment, and the epimera sometimes of the third, and usually of the fourth, 

 fifth, and sixth segments, but not of the seventh, are dark or nearly black, and 

 the color extends distinctly to the adjacent regions of the fourth segment, and 

 may extend across the back along the hinder margin of this segment ; the 

 next two segments may be similarly, but less strongly marked. On the pleon 

 the color appears as a curved or crescentic band, along the lateral margins of 

 the second, third, and fourth segments, and across the back part of the fifth and 

 fore part of the sLxth segments. On the sixth segment the color when present 

 is divided by the median line into two more or less distinct spots, or maculae. 

 The posterior part of the telson is lighter-colored than the body. 



This species has also been obtained by the U. S. Fish Commission at the fol- 

 lowing stations : — 



A single specimen, probably of an undescribed species of this genus, was ob- 

 tained at Station 344, Lat. 40o 1' N., Long. 70° 68' W., from 129 fathoms. 



