98 RHINOCANTHA. 



lonotus, as I commenced it with those species most resembling 

 the true Murices ( Tribulus group). It is readily recognized by 

 its form, its peculiarly rough, scabrous and nodulous surface, its 

 close succession of frills on the varices,its dark chocolate bands, 

 particularly visible on the outer lip, its tuberculate columellar 



lip, frequently also tinged with chocolate. 



West Indies. 



M. Mexicanus, Petit, (fig. 188), and M. oculatus, Reeve, are in 

 no way distinguishable. The description of M. 8alleanus,A. Ad., 

 also applies well to this species, and a specimen received re- 

 cently from Mr. Sowerby under this latter name is certainly 

 identical. I figure the embryonic shell, enlarged, and a group of 

 egg-cases from St. Thomas, W. I., (pi. 7, figs. 72, 73). 



Sub-genus Rhinocantha H. & A. Ad. 

 M. BRANDARIS, L. PI. 21, figS. 193-195. 



Med., W. C. of Africa. 



A variety of this species with three rows of spines, occurring 

 at Gibraltar, has been separated as distinct by Frauenfeld, who 

 has revived for it the name M. trifariospinosa, Chemn., but as 

 Yon Martens has shown (Zool. Record, 1869), the character is 

 not constant, and sometimes only one instead of the usual double 

 row of spines occurs. Eaten by the poorer classes but not much 

 esteemed. 



M. CORNUTUS, L. PI. 21, figs. 196-198. 



W. G. of Africa. 



The curious variety which Mr. Sowerby calls M. tumulosus, 

 (fig. 198), whilst unmistakably belonging to this species yet, by 

 its smaller size, short, direct spines and general aspect indicates 

 a tendency towards M brandaris. The two species, though 

 closely allied, are readily distinguished ordinarily. Is M. tumu- 

 losus a hybrid ? 



Sub-genus Homalocantha Morch. 



M. SCORPIO, Linn. PL 25, fig. 225. 



The color of this well-known type varies from pure white to 

 chocolate-brown, the varices and spines being generally dark 



colored. Length, 1*5-2 inches. 



Moluccas, Philippines. 



