ON MOLLUSCA OP THE WEST COAST OP NORTH AMERICA. 367 



Atlantic states, and have more the general appearance of old world forms. 

 The few known from Mazatlan are essentially tropical in type, and differ from 

 those found on the east of the Rocky Mountains. 



89. The Bryozoa are included in this Report, because it appears univer- 

 sally acknowledged that they have more in common with the lower Tunicata 

 and the Molluscan type in general, than with the Radiata. What few are 

 known have been described by Mr. G. Busk, who regards one species as 

 identical with a British form, another with a specimen dredged by Mr. Darwin, 

 from 96 fms. in Chiloe, a third with a tertiary fossil from Vienna, and the 

 rest as new. 



90. Of the Pteropods nothing is known ; of the naked Gasteropods only a 

 few forms from Sitcha and Oregon ; of the Palliobranchiata scarcely any ; 

 and of the Cephalopods only two, not characterized, from the Behring Sea. 



91. It would be extremely interesting, after comparing the West Ameri- 

 can shells with other existing faunas, to carry our researches back in time, 

 and compare them with the fossils known to occur on the same coasts. For 

 such inquiries, however, there exist scarcely any materials. All that we know 

 is a little concerning the fossils of Oregon in the tenth volume of the ' U. S. 

 Exploring Expedition,' Geology, by Jas, D. Dana. In Appendix I. p. 723, 

 the following fossil shells from the sandstone of Astoria are described. 



Astorian fossils. 



Teredo substriata,Com\[=Dentalium*.~\ 

 Mya abrupta, Conr. [Wanopcea.] 

 Thracia trapezoides, Conr. 

 Solemya ventricosa, Conr. 

 Tellina arctata, Conr. 



emacerata, Conr. 



albaria, Conr. 



nasuta, Conr. 



bitruncata, Conr. 



IDonax pretext a, Conr. [?cast of Solemya.'] 

 Venus bisecta, Conr. 



angustifrons, Conr. 



lamellifera, Conr. 



brevilineata, Conr. 



Lucina acutilineata, Conr. 

 Cardita subtenta, Conr. 

 Nucula divaricata, Conr. 



impressa, Conr. [Leda.~\ 



Pectunculus patulus, Conr. 



■ nitens, Conr. [resembles Limopsis.'] 



The " Dolium " is interesting from its close resemblance to the anomalous 

 Argobuccinum nodosum =■ Cassidaria setosa, Hinds. 



Of the tertiary fossils of the United States, while many Atlantic species 

 occur, none have been noticed exclusively Pacific. There are some few 

 which are found in both oceans ; and a Vermetus, among Mr. Nuttall's Clai- 

 borne fossils, closely approaches V. eburneus, while it differs from the West 

 Indian forms. These fragments of information are all that are yet accessible. 



Area devincta, Conr. 



, sp. 



Pecten propatulus, Conr. [B.M.] 

 Terebratula nitens, Conr. 

 Bulla petrosa, Conr. 

 Crepidula prorupta, Conr. 



, sp. 



Turritella, sp. 



Cerithium mediate, Conr. 



? Rostellaria indurata, Conr. [resembles 



Strombus vittatus.~\ 

 Sigaretus scopulosus, Conr. [? Naticina.~] 

 Natica saxea, Conr. 

 ? Dolium petrosum, Conr. 

 ? Buccinum devinctum, Conr. 

 Fusus geniculus, Conr. 



corpulentus, Conr. 



Nautilus angustatus, Conr. [?=iV. 



zigzag.] 



92. The object of this Report has been so to condense and arrange the 



existing materials that those who consult it may know what has been done, 



and may have the means of deciding on the value to be attached to different 



sources of information. Thus they may be enabled to begin where the writer 



* The notes in [ ] are added by Mr. S. P. Woodward, who kindly furnished the above list. 



