408 CRUSTACEA. 



as long as the first thoracic segment; the second pair long 

 and robust ; the hand thick, with a strong spine near the base 

 beneath, which is met by the finger when bent. The three 

 posterior pairs slender, the penultimate joint with a small 

 spine or tubercle, meeting the nail when closed, as in the hand 

 of the second pair. 



Length of body, 1'4 inch. 



Hab. Throughout the Strait : motion barely perceptible. 



ISOPODA. 

 ARCTURUS BAFFINI (Sabine). 



Idotcea Baffini, Sab., Append, to Parry's Voy. p. 50. t. i. f. 4-6. 

 Arcturm tuberculatm, Latr., Eeg. An. Cuv., ed. 2, iv. p. 139. 

 Arctunis Baffini, Westwood, Trans. Ent. Soc. i. p. 72; Edw. Hist. 

 Nat. Crust, iii. p. 123. t. 31. f. 1. 



IDOTvEA ENTOMON (Lin.). 



Oniscus Entomon, Lin., Faun. Suec. et Syst. Nat. 

 CymotJioa 'Entomon, Fabr., Ent. Syst. ii. p. 605. 

 Idotcea Entomon, Bosc. Latr. ; Edw. Crust, iii. p. 128. 



Numerous fine specimens of these two species of Isopods 

 are in the collection. 



PYCNOGONID^. 



NYMPHON HIRTIPES. 

 PLATE XXXV., fig. 3. 



Pedipalparum digito mobili curvo, digito immobili multo superante ; 

 pedibus omnibus hirtis. 



The rostrum is cylindrical, rounded at the apex ; head with 

 the anterior margin notched; the footjaws rather slender, the 

 second joint having the immovable finger straight, the mov- 

 able one much longer and moderately curved ; the palps of 

 the footjaws, or first pair of articulate appendages, five-jointed, 



