<S54 



PROCEEDINdS OF THE NATIONAL MUSEUM. 



6i. ARCTURUS BERINGANUS Benedict. 



Aretitrus heringanus 15exp;dict, Proc. Biol. Soc. Washington, XII, 1898, pp. 46, 47. 

 Habitat. — Alaska j Bering Sea. 



62. ARCTURUS LONGISPINIS Benedict. 

 Arcturua longispinis Benedict, Proc. Biol. 8oc. Washington, XII, 1898, pp. 44, 45. 

 Habitat. — Aleutian Islands. 



63. ARCTURUS INTERMEDIUS, new species. 



Head, with a deep excavation on its anterior margin, the anterolateral 

 angles being produced in a double i^rocess, the inner one rounded, the 

 outer one acutely pointed. Near the anterior margin in the median line 



is one large spine. Just back 

 of the eyes and between them 

 are two long spines. The lat- 

 eral margins of the head are 

 jjroduced in two small angula- 

 tions with a rounded sinus be- 

 tween, posterior to the double 

 anterolateral process. On the 

 post-lateral margin on either 

 side of the head is a small spine. 

 The first pair of antenute are 

 small and short, not reaching 

 to the end of the second joint 

 of the second pair of antennfe. 

 The first joint of the second 

 pair of antenntb is visible and 

 unarmed; the second joint is 

 armed with three spines; the 

 third joint is unarmed, and is 

 about twice as long as the 

 second joint; the fourth and 

 fifth joints are about equal in 

 length and areeach about twice 

 as long as the third; the flagellum contains three joints. 



The first, second, and third thoracic segments have a transverse row 

 of six large si^ines, three on either side of the median longitudinal line, 

 the two center ones being the longest, although all are very long. The 

 fourth segment is twice as long as any of the other segments, and has 

 a transverse constriction on the posterior half of the segment. On the 

 anterior portion are six spines, three on either side of the median line, 

 the four outer ones being in a straight line, the inner two below this 

 line. On the posterior portion are six spines also, three on either side 



Fig. 28.— Arctuhcs intermedius. x 10. 



