FUSING. 59 



F. TORULOSUS, Lam, PI. 36, fig. 136. 



Chestnut-brown, the nodules lighter and their interstices 

 darker. Length, 6 inches. 



Red Sea f 



Perhaps more robust and more boldly sculptured as well as 

 darker color than the average F. distans, yet scarcely distinct 

 enough to be separated from it. 



F. ASSIMILIS, A. Adams. 



The description of this unfigured species will suit any species 

 of the group, and it is said to resemble in form and sculpture 

 the F. turricula except that the whorls are nodosely angulated. 



China Seas. 

 F. AMBUSTUS, Gould. PI. 37, fig. 138. 



Shell yellowish, shaded with brown, so as to appear as if 

 scorched ; spire acute, whorls eight, angular, girdled with elevated 

 threads, and having about eight varicose folds, which disappear 

 on the lower part of the body. Aperture quite small, nearly 

 semicircular; beak nearly straight, and with a very narrow 



channel. Length, 1*75 inches. 



Mazatlan, Guaymas. 



It is evident, from Gould's figure, that his species is a young 

 shell, and 1 think that the adult is the Dupetithouarsi of Car- 

 penter, which he considered equivalent to Novse-Hollandise of 

 Reeve. I have before me a pair of shells three inches long, from 

 Cape St. Lucas, and identified by Carpenter as Dupetithouarsi, 

 Kiener : they are narrower and more graceful than that species, 

 however, and whilst sufficiently resembling an ambustus, also 

 before me, except in much greater size, they cannot, on the other 

 hand, be distinguished from F. spectrum, vai\ Novse Hollandiae. 

 I have indicated the synonymy as it appears to me, but have not 

 sufficient material to justify me in deciding the matter definitely. 



Mr. W. H. Ball has examined a photograph from an original 

 drawing of F. tumens, Carpenter, an unfigured species described 

 from a very young individual, and identifies it with ambustus. 

 The ambustus of Carpenter, Cooper and others = the following 

 species. 



