PASIPHAEIA AMERICANA. 173 



margin. Bate says that in iV. patentissiimis the antennal carina terminates in 

 the posterior margin of tlie carapace, where it is coniluent with the lower- 

 most, sLibmarginal carina. This is not the case in JSF. wcdcrgrcni. 



I have named this species for the artist of the expedition, Mr. A. M. 

 Westergren, whose drawing of the type specimen, colored from the life, is 

 reproduced on Plate F. 



Family PASIPHAEIID^. 



PASIPHAEIA Sav. 

 Meui. sur les Auimaux saus Vertcbres, I. 50, ISlO \_P(isiph<jCii'\.* 



Pasiphaeia americana i^'as. 

 Flute XL v., Fi(f. 1-1\ 



Pasiphaeia cristata americana Fax., Bull. Mus. Comp. Zool., XXIV. 208, 1893. 



Body strongly compressed laterally. Carapace from three tenths to one 

 third as long as the whole body; dorsum extremely compressed but rounded, 

 rising into a thin, triangular, sharp-pointed crest in the median line a little 

 way back of the anterior margin ; anterior margin slightly advanced in the 

 form of a rounded lobe between the bases of the eye-stalks, but not produced 

 to a distinct I'ostrum ; infra-orbital angles rounded, projecting a little beyond 

 the median inter-orbital process ; at the level of the base of the second an- 

 tennae, the margin of the carapace trends backward nearly horizontally, and 

 then turns downward at a right angle (rounded), and also slightly inward, 

 forming an efferent channel from the branchial chamber behind and beneath 

 the basal segment of the .second antenna; on the upper margin of the efferent 

 branchial opening there is a slender, acute, procurved spine ; a low distinct 

 longitudinal ridge runs along the superior half of the branchial area. 



The abdominal segments are rounded dorsally, not carinate, althougli the 

 sixth is strongly pinched in on each side of the median dorsal line. The 

 sixth segment is one third longer than the telson, which is equal in length to 

 the fifth segment ; the posterior margin of the telson is notched in the middle 

 and armed on each side with about eight spines, the outer one the longest, 

 the others diminishing in importance from without inwards. 



The antennules are furnished with a stylocerite on tlie external side of 



* Pasiphtea was chaiiE^ed to Pasiphae by Risso (Hist. Nat. de TEurope Merid., V. 81, 1826), and by 

 Kroyer (Naturliist. Tidsskr., 2 R., I. 453, 1S45), and this emendation has been accepted by G. O. Sars and 

 S. I. Smitb. It seems more probable that Paaiphtieia {j e. Phiedra) was the word iutcndi-d by Savigiiy. 



