AMERICAN JOURNAL 



doubtful whether Currierianus and aureus have been correctly 

 determined ; the three species are quite distinct. 



No. 83. Strephobasis Clarkii, Lea. 



Dr. Lewis is in error regarding varieties approximating plena, 

 Spillmanii and corpulenta. They are all very different from 

 S. Clarkii. 



No. 88. Trypanostoma curtum, Hald. 



This is placed in the genus Trypanostoma because, on the 

 authority of Dr. Hartman, whose paper is published in a recent 

 number of the Am. Jour. Conch., the operculum differs generic- 

 ally from that of Strephobasis. I have satisfied myself that no 

 generic or specific characters of value are to be found in the 

 opercula of the Strep omatido?, ; hence it should be replaced in 

 Strephobasis. 



To this unfortunate species is referred a synonymy embracing 

 eleven species, belonging indubitably to three different genera! 

 I may not take the time to disprove this wholesale reduction of 

 species, and perhaps it is not necessary that it should be done. 

 Dr. Lewis modestly "suggests" the synonymy, not as entirely 

 conclusive but deserving of inquiry ; but it should be distinctly 

 understood that every species should remain unquestioned (in 

 print) unless it can be proved to be a synonym ; otherwise we 

 have " confusion worse confounded." 



Upon the invitation of Dr. Isaac Lea I have carefully re- 

 examined his types of the species included in Dr. Lewis' strange 

 synonymy, resulting in a renewed assurance that my original 

 determinations respecting them were correct. I suspect that 

 some of the supposed synonyms have not been correctly deter- 

 mined. A very large suit of Str. curta was included in Prof. 

 Haldeman's Holston River collection. 



No. 90. Trypanostoma gkadatum, Anthony ? 



If these shells resemble externally a Strephobasis, then I am 

 afraid they have not been correctly determined. 



No. 95. Trypanostoma undulatum, Say. 



Why does Dr. Lewis include this species in his list, when, in 

 the same paragraph, he admits his inability to recognize it? 



I have neither the time nor inclination to demonstrate at 

 length the reasons for believing Dr. Lewis to be in error in all 

 the above instances, and perhaps it is sufficient to indicate the 

 more palpable mistakes as I have done, and in other cases merely 

 express my dissent from his views. As soon as my complete 

 monograph of the family Strepomatidce is published by the Smith- 

 sonian Institution, students will have better means of determin- 

 ing the species correctly than those now available. 



