5() THE NAUTILUS. 



being found in Margaritana arcuata. I have a friend who has done 

 quite a business in collecting them from that mussel." 



E. H. Harn, Blairsville, Pa. in five years, has found 64 species 

 and varieties of shells in his neighborhood. That is a sample of 

 ■what can be done by i^atient search. 



Mrs. M. Burton, Williamson University, Cal. sends us a copy of 

 the Weekly Tribune of Los Angeles, Cal. of August 16th, contain- 

 ing an interesting article by Virginia Burton, upon the" Coffee-bean 

 Cowries" of the California Coast (Trivia Solandri and Trivia Cali- 

 fornica.) 



Mr. Frank C. Baker, who has been studying at the Academy of 

 Katural Sciences of Philadelphia for a year jiast, and who was one 

 of the members of the expedition sent by the Academy to Southern 

 Mexico, has accepted a position with Prof. Henry Ward of Roch- 

 ester, New York, in his department of Invertebrates. Mr. Baker 

 leaves many warm friends in Philadelphia, where he will be missed 

 from the circle of conchologists as well for his kindly personal 

 qualities as for his recognized ability in the study of Mollusks. 



THE SHELL-BEAKING MOLLUSCA OF RHODE ISLAND. 



BY HORACE F. CARPENTER. 



FAMILY UNIOXID.E. 



Genus Anodonta, Cuvier. 



Shell transvei'sely elongated, inequilateral, thin, toothless. 



To distinguish instantly between the three genera, Unio, Mar- 

 garitana and Anodonta, it is only necessary to examine the hinge. 

 Unio has cardinal and lateral teeth in each valve ; ^Nlargaritana has 

 cardinal teeth, but no laterals, while Anodonta has no teeth, the 

 valves being held together only by the ligament. 



There are two hundred species of Anodonta, distributed world 

 wide. Two of these are known to inhabit R. I., and a third may 

 possibly be found Avithin its limits. 



193. — Anodonta catarada. Say. 

 Syns. : 



Anodonta jiMviatilis, Lea, Gould, Stimp. 



Mxjtillus illietus, Solander. 



Shell thin, inflated, transversely sub-oval, fragile ; basal margirr 

 curved ; hinge margin straight ; epidermis smooth, excepting at the 



