634 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 40. 



The legs of the first pair are prehensile, of the following six pairs 

 ambulatory. 



The type of the genus is Jserella armata, new species. 

 This genus is closer to Iolella (as represented especially by /. spinosa 

 (Harger), I. speciosa (Bovallius), and I. glabra Richardson) than to 

 any other genus of the family, but differs from it in having the antero- 

 lateral angles of the head as well as the lateral margins produced in 



triangular processes; in having the last 

 three segments of the thorax produced in 

 two elongate processes instead of one; in 

 having the abdomen produced in two pos- 

 terior triangular processes and two lateral 

 triangular processes instead of the two 

 posterior triangular expansions found in 

 that genus; and in having four spines on 

 the fourth segment of the thorax. This 

 genus may also be compared with Rhacura 

 Richardson, 1 AcantJiaspida Stebbing, 2 lolan- 

 ihe Beddard, 3 and lanihopsis Beddard. 4 



JiERELLA ARMATA, new species. 



Body oblong-ovate. 



Head with anterior margin produced in 

 the middle in an extremely long rostrum, 

 ending acutely. Antero-lateral angles also 

 produced forward in extremely long pro- 

 cesses, one on either side, almost as long 

 as the rostrum. Below these the lateral 

 margin is produced on either side in a long 

 process, extending almost as far as the 

 antero-lateral process. Eyes large, rounded, 

 and situated some distance from the lateral 

 margin, on the posterior half of the head. 

 Between the eyes on the dorsal surface are 

 two long sharp spines, one on either side of the median line. The 

 first pair of antennae extend to the middle of the last peduncular 

 article of the second pair of antennae. The second pair of antennae 

 have the first four articles short and about equal in length; the 

 fifth is a little longer than the first four taken together; the sixth is 

 a little longer than the fifth; the flagellum is broken in the only 

 specimen. 



1 Proc. U. S. Nat. Mus., vol. 35, 1908, pp. 72-74. 



2 Norwegian North-Atlantic Expedition, XIV, Zoology, Crust., vol. 1, 1885, pp. 119-121, pi. 10, figs. 27-30. 



3 Challenger Eeport, Zool., vol. 17, pt. 48, 1886, pp. 15-18, pi. 4, figs. 9-14; pi. 5, figs. 1-4. 



! Idem, p. 15, pi. 5, fig. 5. Also Studer, Abh. k. Akad. Wiss. Berlin,1883, pp. 10-12, pi. 1, fig. 2. 



FIG. 1. — JiERELLA ARMATA. X 11 



(Drawn by Miss V. Dandridge.) 



