ON MOLLUSCA OF THE WEST COAST OF NOKTH AMERICA. 613 



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

 series of two forms should not he allowed to unite them, but he considered 

 as hybrids." 



Lunatia Leioisii. Abundant on beach. [One sp. measures 5J 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, 0. hirida, are well-marked .''vars. laticaiMata, 

 rtif aides, 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 

 axe 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 PTOraaa. 



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



620a. Figm-e accords exactly with Venus toremna, Gld. Catalina Is., beach. 

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

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



676. Resembles CrassaieUa Pcudfica. 



874. Liicina. 



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



— Yoldia. One fresh valve of a large and remarkable species, 2'6 by 1'3 in., 



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

 751a. ?Ianthina. 

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



— ?Gadima. Cat. Is., Cooper; Faralloue, Is., JiotoeU. "The animal differs in 



having pectinated flattened tentacles. It may be the type of a new genus 



ItoweUia." 

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

 415a. Glyphis. 



354a. Like Haplocochleas. Sta. Barbara, 15 fm. 

 564. Like Fyrgola. 40 fm. 



— Ti-ivia sanguinea. Dredged dead in Cat. Is. 



— Trivia. " Thinner and larger than «ore^«nea. Common in Lower Cal." [? = 



Pacj/?oo.] 



— " Terebra specUlata." One sp. near S. Pedro. 



— Pleurotomidce. Several species are represented only by single specimenj". 



Among them are 



588. Brillia. 



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

 1020. DWZ&a, reversed. Catalina Is., 60 fm.,. living. 



479a. ClathnreUa (large). Sta. Barb., 20 fm. 



663. ClathureUa, 15 fm., Sta. Bai-b. 

 1852. ? ClathureUa, iDim. 

 1053. ?Daphnella, 60 fm. 



419, 426. Two species of shells resembling Daphnella, 

 1055. P^eZa, 80fm. 



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



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

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

 a young Vermetid.] 



463. " Cancettaria ? Tritanice, Shy. Agrees with Dr. Newcomb's specimen." f^. 

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



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

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

 1050. Lamellarin. 10 fm., Sta. Barbara. 

 r385a, 464, 818.) Naticid<B. 3 sp. 



101 



