104 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 37. 



the second antennae shorter (the second article is 3 mm. long, the 

 third is 9 mm., the fourth is 14 mm., the fifth is 13 mm.) ; in having 



the spines of the head and of the second, 

 third, and fourth segments of the thorax 

 stouter and longer; in having the body 

 shorter and more thickset (8 mm. : 30 

 mm.), and densely covered with hairs; 

 and in having the abdomen below the 

 median dorsal spines shorter. The first 

 antenna? do not extend beyond the sec- 

 ond article of the second antennas. 

 The young are similar to the adults. 

 A number of specimens (about twelve) 

 were collected at station 4777, on " Petrel 

 Bank," Bering Sea, at Semisopochnoi 

 Island, r. t. S. 44° W., 1. t. S. 4° W., 

 about 12 miles (lat. 52° 11' N.; long. 

 179° 49' E.), and station 4778, r. t. S. 

 45° W., 1. t. S. 12° W., about 12 miles 

 (lat. 52° 12' N.; long. 179° 52' E.), at a 

 depth of 43-52 fathoms. 



One small specimen from station 4779 

 agrees in every respect with the other 

 specimens, except that the terminal seg- 

 ment, instead of terminating in two 

 points, is rounded posteriorly. This is 

 j)robably an abnormal condition. 



Type-specimen. — C at. No. 39327, 

 U.S.N.M. 



ARCTURUS DIVERSISPINIS, new species. 



This species is also close to Arcturus 

 longispinus Benedict, but differs in hav- 

 ing the tubercles of the first thoracic seg- 

 ment replaced by well-developed spines, 

 Avhich are almost as long as those of the 

 three following segments, and in having 

 the spines of the seventh thoracic seg- 

 ment rudimentary. The first antennae 

 extend the length of the last article be- 

 yond the second article of the second 

 antennas; the last article of the first an- 

 tennas is about twice as long as the pre- 

 ceding article. There is a small, blunt spine on the outer distal end of 

 the second article of the second antennas, and one on either side of the 



Fig. 27. — Arcturus d i x e r s i- 

 spinis. X 1.2. Female. 

 (Drawn by Miss V. Dandridge.) 



