JiARGitjfiLLA, Panama &helh> 41 



Station. — From 5 to 13 fathoms sandy mud ; Hinds ! copied 



by Sowerby. 



We found these molluscs on a flat of liquid mud, a little 



above low water mark. On the surface of this mud they, 



were moving about with great vivacity while the tide was out. 



Habitat. — Panama ; Hinds ! copied by Sowerby. 

 Panama ; E. Jewett ! Gould Mss. 

 Panama ; C. B. A. ! 



Mr. Hinds calls this species " the American analogue " of 

 M. prunum Gm. (syn. M. coerulescens Lam.) but Mr. Sowerby 

 assigns M. prunum to Panama as its habitat ! A little east 

 of Panama we obtained 40 living specimens of M. sapotilla, 

 and also collected many dead shells on the beach above the 

 muddy flats. No specimen of M. prunum was found. The 

 latter, however, occurs abundantly in some parts of the Ca- 

 ribbean sea. We have obtained in Jamaica a large number 

 of this species, said to have been taken on the keys south of 

 that Island, and the Hon. Edward Chitty, of J., kindly gave 

 us a parcel said to have been collected at Cura^oa. Inde- 

 pendently of the testimony, the other shells, which were 

 mingled with these parcels, were all Caribbean] species. 

 Without affirming anything respecting the existence of M. 

 prunum on the west coast of Africa,* we may therefore safely 

 say that it is the Caribbean species, — as M. sapotilla is the 

 Pacific species — of tropical America, 



' • Mr. J. H. Redfield, the best authority in reference to thig genua, iDforms me 

 that be has examined many parcels of shells collected in the Gambia region, at 

 Cape Palmas, and the I. of St. Thomas, in the Gulf of Guinea, and has never been 

 able to find any evidence that the M. prunum inhabits West Africa. Mr. It. sug- 

 gests that by some means Adanson may have been in error, and that his error bag 

 been simply copied by all subsequent authors. 



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