MT REX. 81 



and there are also one or two on each varix below the aperture. 

 The color varies from whitish to livid with two or three broad 

 brown bands which are most visible within the aperture. 



West Indies ; W. Coast of Central America to Mazatlan. 



Having a very extensive suite of this species, including 

 specimens from well-authenticated localities on both sides of the 

 American continent, I find no difference in them whatever as to 

 the typical form described above, and which may be recognized 

 at once by its general dark color. M. nigrescens, Sowb. (fig. 

 124), is simply a large specimen of the typical form and M. livi- 

 r/w.s, Carp., cannot be distinguished as a variety. M. funiculatus, 

 Reeve (fig. 112) is founded on an unusually light colored specimen ; 

 similar ones are in the collection before me as well as examples 

 of intermediate coloration. M. messorius, Sowb., (fig. 125), is 

 similar to M. f-uniculatus and also has relationships with the form 

 with straight canal which the same author has named M. rec- 

 tirostris, (fig. 126). 



There is also a West Indian form, much lighter in color, and 

 with the spines usually somewhat more developed whilst the 

 canal is generally shorter. If I had fewer specimens I might be, 

 able to distinguish this form as a variety, but my material sup- 

 plies all intermediate gradations. Of these lighter-colored shells 

 Sowerby has made his M. similis (fig. 130), whilst another specimen 

 has been figured by him in mistake for M. motaciUa, Chemn. 

 Two eager English conchologists discovered this error and Mr. 

 Hinds has added to his scientific laurels by describing the 

 wrongly identified shell as M. Antillarum, whilst Mr. Reeve has 

 called it M. nodatus and refigured it. Of course neither of these 

 investigators felt called upon to study the group to which Mr. 

 Sowerby 's wrongly identified species belonged and equally of 

 course neither of them had time to ascertain whether any other 

 naturalist had made and published a similar discovery. Thus I 

 place eight so-called species in the synonymy of M. recurvi- 

 rostris in addition to a number of synonyms acknowledged by pre- 

 ceding authors and upon which I therefore refrain from dwelling. 

 Mr. Arthur Adams has issued a short Latin diagnosis (Zool. 

 Proc. 1851), of M. pulcher from St. Croix, W. I. No figure has 

 been published and the description mentions neither color, 

 11 



