INSTITUTE OF SCIENCE, PHILADELPHIA. 27I 



South Carolina, and was described as a Cerithiiivt as follows : " Turreted ; 

 volutions eight or nine, angular and carinated below the middle ; body-whorl 

 bicarinated. Length, |-." C. claibornensis Conrad appears to be a fragment of 

 a Ceritliium. C. solitaria Conrad is a Cerithmm and not a Cerithiopsis. De 

 Gregorio refers Ceritliium tombigbeensis Aldrich to solitaria, but the figure of 

 the latter does not at all resemble Aldrich's shell. The above are all Eocene 

 forms. C. oregoiiensis Conrad was first recorded as an unidentifiable fragment 

 by that author, who at a later date named his own extremely bad figure of it. 

 It is uncertain whether it came from the Eocene or the Miocene Astoria bed, 

 as Conrad had fossils from both and did not discriminate them. C. Emmonsi 

 Conrad, from the Miocene of North Carolina, is a Columbellid belonging to 

 Seminella or ySsopus, which was figured as an unnamed species of Ceritliium 

 by Emmons. From the California. Pliocene Carpenter has described a Cerithi- 

 opsis assimilata, and from the Costa Rica clays of the same age a species has 

 been described as Ceritliium limonensis Gabb which appears to be a Ceritlii- 

 opsis. Another species described in Gabb's posthumously published paper 

 under the name of Ceritliium caribbaiim recalls Cerithiopsis, but is probably a 

 species of Oscilla. His Cerithimn rtioenensis is an Alaba not far from A. ter- 

 varicosa Adams. 



Family CERITHIID^. 

 Genus BITTIUM (Leach MS.) Gray. 



I have not been able to confirm Monterosato's supposition that this name 

 had been used for a genus of Crustacea, either before or after 1847, and con- 

 clude that some mistake has misled him. At all events, one can reasonably 

 claim the right to retain the name until the preoccupation of it is established 

 by definite citations. 



This group includes a variety of small Cerites which have no posterior 

 notch to the aperture and no defined canal ; the outer lip is patulous and the 

 last whorl usu^ly contracted and overhung by its predecessor. The species 

 are extraordinarily variable in sculpture, the typical forms are varicose, but 

 the majority are not distorted by the varices, which are frequently feeble and 

 few in number. Some species like B. alternatum Say have the varices so 

 thin that they are only visible as an impressed line. Diastema differs from 

 Bittium by having a notch or feeble posterior canal in the outer lip. Some 

 shortj ovoid species like Sandbergeria valmondoisiensis Cossmann are almost 

 Rissoid in form. That author has referred them to Sandbergeria as a section 

 Aneiirychilus, but to the writer they seem rather more closely related to Bit- 

 tium. Alaba is another form which differs from Bittium in but few characters. 

 Litiopa is much modified by its pelagic habit, but with Alaba forms a group 

 which can hardly be regarded as far distant from the Cerithiidce. The sec- 

 tions and subgenera into which the Lamarckian Cerites have been divided, 

 subtraction made of forms like Triforis and Cerithiopsis, are not separated 



