90 AMERICAN JOURNAL 



Fusus Remondii, F. Hornii and F. Cooperii are all members 

 of the subgenus Hemifusus, none of them resembling Perisso- 

 lax, the first least so of all. Mr. Conrad does not appear to 

 understand the generic character of Perissolax. I founded 

 the genus in 1861, to receive a division of the genus Fusus 

 having a form almost like Tudicla or Haustellum ; that is to 

 say, with a very low spire; short, thick set body whorl, and 

 a long, narrow canal. I mentioned, as types of the genus, F. 

 h/ngirostris^ D'Orb., and F. frivolous, Gabb, and remarked, that 

 the genus seemed to be peculiar to the Cretaceous. Mr. 

 Conrad appears to misunderstand the peculiar characters of 

 tlie genus, and to apply the name to a totally different 

 group of shells; ignoring my two types, both of which are 

 Cretaceous species, and saying: "This genus is peculiar to the 

 Eocene formation." 



Perissolax hrevirosfris, G. Subsequent study has confirmed 

 me in the opinion that this shell was correctly placed under 

 the genus Perissolax, although its unusually short canal caused 

 me to hesitate at first. It is probably an extreme form. 



Naticina ohliqua and Turrildla Uvasana. Said by Mr. Con- 

 rad to be Eocene species. Both of these shells have been 

 found by Mr. Rcmond and myself in strata containing Am- 

 monites and BacvJites, and abounding in other Cretaceous forms. 



Amauropsis alveata, Gabb. Cal. Eeport. 



Natica alveata, Con. Pacific E. E. Eeport. Mr. Conrad 

 says: "Is a species of Glohularia, and occurs, I think, in the 

 Older Eocene Limestone of South Carolina, or a species very 

 near to it." In his original description of the species, he re- 

 marks: "There is no analogous species in the Eocene of the 

 Atlantic slope." He says 1 have figured two speci(;s, because 

 I illustrate two diverse forms. Being limited in space. I only 

 figured the extreme varieties. The angle of the upper por- 

 tion of the whorl varies from one form to the other, and the 

 striation of the surface is equally inconstant. Hardly two 

 specimens are exactly alike. The majority of the specimens 

 show revolving lines on at least a part of the surface; those 

 from San Diego being the only ones on which I was unable 

 to detect lines on some portion, and only a single specimen, 

 one from Curry's, south of Mt. Diablo, showed the whole sur- 

 face strongly striate. This variation is not dependent on the 

 geological horizon, as Mr. Conrad represents me as saying. 1 

 made no such remark as he quotes. 



