90 OPISTHOBRANCHIATA OF BRAZIL 



Body somewhat elongate, not depressed. Rhinophores per- 

 foliate. Anterior angles of foot not prominent. Cerata cylindro- 

 conical, arranged in groups, each of which is borne upon a 

 slight, crescentic, dorso-lateral elevation of the integument. 



Masticatory margin of mandibles long, minutely denticulate, 

 or smooth. 



Radula uniserial, the teeth pectinate, emarginate in the center. 



This genus was proposed by Bergh in 1864 for the reception 

 of Delle Chiaje's Eolis neapolitana as the type species. In 1871 

 he transferred to this genus a second species, Sp. sargassicola 

 (Kroyer), and in 1882 and 1885, in the papers cited above, made 

 further additions to the knowledge of the anatomy of the type 

 species, which had been already extensively studied by Trinchese 

 in 1878. Vayssiere added to this in his excellent researches 

 upon the Opisthobranchs of the Gulf of Marseilles, in 1903 

 recognizing a third distinct species, Sp. inornata (A. Costa). 

 The Siboga collections contained a fourth species, which was 

 described by Bergh in 1905 in his beautiful work upon the 

 Opisthobranchiata of that expedition. 



At the present time the list of species described as belonging 

 to this genus is the following: 



1. Spurilla neapolitana Delle Chiaje). 



Mediterranean, Cape Verd Islands. 



2. Spurilla sargassicola (Kroyer). 



Sargasso Sea, Atlantic Ocean. 



3. Spurilla inornata (A. Costa). 



Mediterranean. 



4. Spurilla orientalis Bergh. 



Kei Island, Malay Archipelago. 



All three of these species are closely related, the first two 

 being held by Bergh to be questionably distinct. The following 

 description deals with the first member of this genus thus far 

 taken from the West Atlantic. After a careful comparison of its 

 structure with that of Sp. neapolitana, and with the description 

 of the others, I am of the opinion that it represents a distinct 

 species, though certainty in this regard can only be secured by the 

 study of a series of specimens. 



