THE NAUTILUS. 



VOL. XVI. MARCH, 19O3. No. 11. 



ON THE SPECIFIC VALIDITY OF CAMPELOMA MILESII LEA. 



BY BRYANT WALKER. 



There has been considerable difference of opinion expressed, both 

 in regard to the specific validity of this form and in regard to its 

 relations to the other recognized species of the genus. 



The types were collected by the late Manly Miles, formerly State 

 Geologist of Michigan, in Branch Lake, Antrim county, in the ex- 

 treme northwestern part of the State, and were described by Dr. Lea, 

 in 1863. ' Binney, in 1865, 2 included it in the aggregation which he 

 assembled around Gampeloma decisa. Dr. James Lewis, in his re- 

 view of Binney's work in the Am. Jour, of Conchology, 3 declared 

 that it " has claims to the rank of a species that must be recognized." 

 And later, in the same Journal, 4 associated it with decisa in the group 

 characterized by " shells of thin texture, whorls usually regularly 

 rounded, suture well impressed, spire regular in proportion and, when 

 perfect, acute." 



Tryon, in his continuation of Haldeman, 5 concludes that " it does 

 not exceed the usual variation of decisa," and does not allow it even 

 varietal rank. Call, in his elaborate paper " On the Genus Campe- 

 loma," 6 refers it to C. subsolida Anth. And in this he is followed 



c. Phil. Acad. Nat. Sci., 1863, p. 156. 

 3 L. & F. W. Shells, Pt. Ill, p. 42 (1865). 

 S A. J. of C., IV, p. 60 (1868). 

 *A. J. of C., V, p. 33 (1869). 

 5 Mon. F. W. Univalve Moll., p. 28 (1870). 

 8 Bull. Wash. Coll. Lab. N. H. I., p. 155 (1886). 



