124 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 37. 



Fig. 47. — Prophryxus ala- 

 scensis. Dorsal view 



OF ADULT FEMALE. X 19g. 



Avatcha Bay, Kamchatka, at Toporkov Island, harbor of Nikolski, 

 Bering Island, at a depth of 2,700 fathoms; it was parasitic on 



Eucopia australis. 



PROPHRYXUS, new genus. 



Body of adult female irregular in outline. Head and first three 

 segments of thorax defined. Last four thoracic segments indicated 



only in the dorsal region. Lateral parts of 

 thorax swollen and extending backward in a 

 small rounded lobe on either side. 



Five abdominal segments defined. Pleo- 

 pods rudimentary. 



Five pairs of legs surround the oral area. 

 Male unknown. 



Type of genus. — Prophryxus alascensis. 



PROPHRYXUS ALASCENSIS, new species 



Body of adult female oval in outline, with 

 the front somewhat quadrangular, more or 

 less depressed. Lateral parts of body swollen, 

 but not projecting anteriorly. Head extend- 

 ing straight in front, with the anterior mar- 

 gin straight. Two little black spots on one side may represent one 

 eye. Head indistinctly defined from thorax. 



The first three segments of the thorax are indistinctly indicated; 

 they extend from one side of the body to the other. The following 

 four segments are only indicated in the mid- 

 dle of the dorsal region. The lateral parts 

 of the thorax are expanded and unsegmented, 

 and extend backward in a small posterior 

 lobe on either side of the abdomen, reaching 

 almost to its extremity. 



The abdomen consists of five indistinctly 

 defined segments, indicated more on one side 

 of the body than on the other. The fifth or 

 terminal segment is bilobate. 



In a ventral view of the body there are 

 five pairs of legs surrounding the oral area. 

 There seem to be rudimentary pleopods. 



Only one specimen was obtained at sta- 

 tion 4759, on the way from Union Bay, Brit- 

 ish Columbia, to Dutch Harbor, Alaska, by the Goletas Channel and 

 Unalga Pass, at lat. 53° 05' N. ; long. 138° 31' W. It was taken at a 

 depth of 2,000 fathoms with a schizopod, but unattached. 

 Type-specimen.— Cat No. 39523, U.S.N.M. 



Fig. 48. — Prophryxus ala- 

 scensis. Ventral view. 

 X 191. 



