ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 615 



species, and that the comparatively few links that are met-with in large 

 series of two forms should not be allowed to unite them, hut be considered 

 as hybrids." 



Lunatia Lewisii. Abundant on beach. [One sp. measures 5f in., and the 

 animal of a much smaller one (4 in.) is 11 inches long.] 



Ostrea. " The same species throughout to S. Franc. : S. Diego," Cooper. [Be- 

 sides the typical northern shell, O. lurida, are well-marked Pvars. laticaudataj 

 rufoides, and expansa.~] 



There are also several species which are quoted in Dr. Cooper's letters, or 

 appear from his sketches to be quite distinct, or at least new to the fauna : 

 but they have not yet been sent for identification. Among these the following 

 are the most important. The MS. numbers refer to the tracings which Dr. 

 Cooper kindly copied from his original drawings. Where a " " appears, 

 the information is derived from his letters only. 



MS. No. 

 402. Allied to ?Thracia. 



Cyathodonta, probably plicata, Desh. (Cape St. Lucas, Xantus). 



6200. Figure accords exactly with Venus toreuma, Gld. Catalina Is., beach. 

 1058. Figure accords with Lioconcha hieroqtyphica. Catalina Is., 120 fin. 

 1060. Resembles Sunapta. Catalina Is., 40 fin. 



676. Resembles Crassatella Pacifica. 



874. Lucina. 



983. Nucula, with concentric sculpture. Sta. Barbara, 15 fm. 



Yoldia. One fresh valve of a large and remarkable species, 2-6 by 1-2 in,, 



with fine concentric sculpture, very inequilateral. Sta. Cruz ; on beach. 

 751a. ?Ianthina. 

 1077, 1078. Chitonidee. Two highly sculptured species. Sta. Barbara, 12 fm. 



?Gadinia. Cat. Is., Cooper; Farallone, Is., Rowdl. "The animal differs in 



having pectinated flattened tentacles. It may be the type of a new o-enus 



Rowellia." 



466. Emarginula. [The first appearance of the genus on the W. American coast.] 

 4155. Glyphis. 



354. Like Haplocochleas. Sta. Barbara, 15 fin. 

 564. Like Pyrgola. 40 fm. 



Trivia sanguined. Dredged dead in Cat. Is. 



Trivia. " Thinner and larger than sanguinea. Common in Lower Cal." [?=s 



Pacifica.'} 



" Terebra specillata" One sp. near S. Pedro. 



Pleurotomidce. Several species are represented only by single specimens. 



Among them are 



588. Drillia. 



1021. Drillia, 2 in. long, shaped like Mitra. One worn sp. Catalina Is.. 120 fin, 

 1020. Drillia, reversed. Catalina Is., 60 fm., living. 



479rt. Clathuretta (large). Sta. Barb.. 20 fm. 



663. Clathuretta, 15 fm., Sta. Barb. 

 1852. ?Clathurella, 40 fm. 

 1053. ?Daphnella,6()fm. 



419, 426. Two species of shells resembling Daphnella. 

 1055. ?ela, 80 fm. 



423a. Mangelia, 15 fm., Sta. Barb. 



3976. Shape of Cithara, without ribs. Catalina Is., beach. 



1028. "?Aclis," reversed. One sp., Cat. Is., 120 fm. [The figure more resembles 

 a young Vermetid. J 



463. " Cancdlaria ? Tritonice, Sby. Agrees with Dr. Newcomb's specimen." g. 

 Diego, one dead on beach, 2 in. long. 



817. Cancdlaria. Fragment of a second species equally large. 

 1038. Sigaretus. 40 fm., dead, Cat. Is. 

 1050. Lamellaria. 10 fm., Sta. Barbara. 

 (385a ; 464, 818.) Naticida. 3 sp. 



101 



