pleurobranchidjE. 37 



Species of Bursatella. 

 laciniata, Riipp. Leachii, Blainv. 



Genus STYLOCHEILUS, Gould. 



Body limaciform, cirrhigerous, dilated at the sides, 

 attenuated posteriorly. Head separated from the body 

 by a distinct neck ; tentacles four, elongated, linear, more 

 or less papillose, wide apart ; mouth inferior, the lips 

 dilated laterally into an acutely-conical tentacular pro- 

 cess. 



Ex. S. longicauda, Quoy and Gaimard, pi. 60, fig. 3. 



The papillose tentacles, and the peculiar lateral ex- 

 tension of the lips, are the chief features of this genus ; 

 the body, moreover, is prolonged behind into an acute, 

 tapering, tail. The four tentacles are quite distinct from 

 the elongate labial processes. 



Species of Stylocheilus. 



lineolatus, Gould. quercinus, Gould. 



longicauda, Quoy and Gaim. 



Fam. PLEUROBRANCHID^. 



Head with auriform tentacles ; eyes sessile on the head, 

 at the bases of the tentacles; mouth provided with an 

 oral veil, corneous jaws, and an armed lingual riband. 

 Gills composed of a double row of leaflets in the form of 

 a long branchial plume at the side of the body under 

 the edge of the mantle. 



VOL. TI. G 



