90 GAMMAR1DJ2. 



A MPHTPODA . L YSIANASSIDES. 



NATATORIA. 



Genus ANONYX, KROYER. 



Anonyx Kroyer. GTRONLANP, Amfip. p. 15 ; Nat. Tidsk. v. ii. p. 256. 



Generic character. Superior antennae short, pyriform, furnished 

 with a secondary appendage. Mandibles having a smooth 

 incisive margin and a palpiform appendage. First pair of 

 gnathopoda subchelate ; second pair long, slender, feeble, and 

 subchelate. Telson single, squamiform, cleft. 



THIS genus was separated from Lysianassa by Kroyer, 

 from the subchelate form of the hands of the third 

 pair of limbs (" parvulo instructi ungue"), and from the 

 fourth pair of limbs being destitute of a terminal hook, 

 (whence the generic name,) the place of which is sup- 

 plied by a brush of hairs. Also the middle tail-piece, 

 instead of being entire, as in Lysianassa, is divided more 

 or less deeply in Anonyx. Neither of these characters 

 are capable of being distinguished without close exami- 

 nation, and in some species, Anonyx lagena for example, 

 the extremely oblique palm of the hand approximates, 

 in its form, to that of a Lysianassa ; again, the divi- 

 sion of the central tail-piece is occasionally so slight, 

 as in A. obesa, that a small depression alone exists. 

 The genus Opis, of which Kroyer has described two 

 species, differs from Anonyx in the opposite extreme. 

 As Lysianassa has a less perfectly chelate hand than 

 Anonyx, so Opis possesses one that is still more perfect 

 as a didactyle claw. 



This grouping, although convenient, appears to us to 

 be arbitrary ; moreover, it is not improbable that some 

 of the forms may be only sexual. 



