12 ANCYLUS FUSCUS. 



towards the right. Professor Adams remarks 

 "It was supposed to be Say's A. rivularis, 

 not on account of any resemblance between 

 the two shells, but from the meagreness of the 

 description. From some remarks of this learned 

 naturalist, comparing A. rivularis with A. tardus, 

 it seems probable that the former is not an 

 elongate species." Appendix to Thompson's 

 History of Vermont. 



ANCYLUS FUSCUS, Adams. 



PLATE 1. FIG. 7. 



A. testa ovata, depressa; apice obtuso; epidermide fusca, 

 ultra quam peritremam producitur. 



SYNONYMS AND REFERENCES. 



A. FUSCUS, ADAMS. Boston Journ. Nat. Hist., vol. iii. p. 



329, pi. 3, fig. 17. 

 A. FUSCUS, GOULD. Invert, of Mass., p. 224, fig. 152. 



DESCRIPTION. 



SHELL thin in texture, ovate, depressed, a 



