O.VM.MAIUDJ';. (33 



2. Pleustes panoplus. (Platk IX. tig. !).) B.M. 



Ampliitoe panopla, Kroifer, Gron. Amf. p. 42, pi. 2. f. 9. 

 Edwards, Hist, des Crust, t. iii. p. 41. 

 Liljebory in Ofrers. of Kong. Vetetisk. Akud. ForhamU. 1851. 



This species differs from P. tuhermlata in the absence of the 

 tuheivlos, particularly upon the posterior portion of the animal, and 

 in the shortness of the rostnim. It is dorsally carinated, and ha.s a 

 ridge traversing the sides. 



Length ^ths of an inch. 



Hah. Coast of Greenland (Kroyer) ; North Atlantic (Barrett). 



c. Stqienor antennce with a rmUmentary ajypendac/e ; mandibles ivith- 

 out an appendage ; posterior pleopoda double-branched. 



5. STEGOCEPHALUS. 



Stegoeephaliis, Kriit/er, Naturtidsk. iv. p. 150. 

 Cephalon short. Antennae short ; superior pair furnished with a 

 seeondaiy appendage. Mandibles without an appendage, with a 

 secondaiy plate only on the left mandible. Maxillipeds ha^■ing the 

 second and third joints produced into a squamiform plate. Gna- 

 thopoda not subchelate. Coxa; of the gnathopoda and the two 

 anterior pairs of pereiopoda very large. The three posterior pairs 

 of pleopoda uniform. Telson squamiform, cleft. 



1. Stegocephalus Ampulla. (Plate X. fig. 2.) B.M. 



Cancer Ampulla, Pldpps, Voy. au Pole Borecde, (App.') pi. 12. f. 2. 

 Gaimnarus Ampulla, ^dhinc, Parry s First Voyage, (Suppl.) p. 229. 



Ross, Parry's Polar Voyage, (Suppl.) p. 204. 

 Lysiana-ssa (?) Ampulla, Edwards, Hist, des Crust, t. iii. p. 22. 

 Stegocephalus inllatus, Kriiycr, Naturtidsk. iv. 150, 1842. 

 Stegocephalus Ampulla, Bell, Belcher's Last of the Arctic Voyages, 

 (App.) p. 406, pi. 35. fig. 1. 



Cephalon very short, being half as long as the first segment of the 

 pereion, produced into a short rostnim, incurved. Pereion arcu- 

 ated and inflated. Pleon a little compressed laterally. Eyes not 

 visible in the dead animal. Superior antennae thicker than the 

 inferior, having the flagellum longer than the peduncle, and 

 fiu-nlshcd wdth a minute secondaiy appendage consisting of a 

 single joint. Inferior antenna) having the peduncle longer than 

 the peduncle of the superior. First pair of gnathopoda scarcely 

 smaller than the second, and uniform witli them. Tlie second 

 pair having the cai-p^s as lu-oad as the propodos ; the inferior 

 margin of the propodos furnislied w^th stout olituso hairs fiiugcd 

 with cilia. Pereiopoda subequal, the coxae of the last three pair.s 



