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, but be considered 

 as hybrids." 



Limatia Leicisii. Abundant on beach. [One sp. measures 5^ 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. laticaialata, 

 ritfoides, and e.vpa)isa.^ 



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, Xanttis). 



G20«. Figure accords exactly with Venus torenma, Gld. Catalina Is., beach. 

 1058. Figure accords with Lioconcha hieroghjphica. Catalina Is., 120 fm. 

 1060. Resembles Simapta. Catalina Is., 40 fm, 



676. Resembles Crassaella Pacifica, 



874. Liicina. 



983. Nucida, with concentric sculpture. Sta. Barbara, 15 fra. 



• — 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. 



751«. flatifhina. 

 1077, 1078. Chitonid(e. Two highly sculptured species. Sta. Barbara, 12 fm. 



— ?Gadiina. Cat. Is., Cooper; Farallone, Is., Roicell. "The animal ditfers in 



having pectinated flattened tentacles. It may be the t}'pe of a new genus 



RoiceUia." 

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

 41ort. Glyphis. 



Zoia. Like Haplocochleas. Sta. Barbara, 15 fm. 

 564. Like Fyrgola. 40 fm. 



— Trivia saiifiinnea. Dredged dead in Cat. Is. 



— Trivia. " Thinner and larger than saw^MiViea. Common in Lower Cal." [?rs 



Pacijica.^ 



— " Terehra i^peciUata.'''' One sp. near S. Pedro. 



— Plcurotomidce. Several species are represented only by single specimen?. 



Among them are 



5S8. DriUia. 



1021. DriUia, 2 in. long, shaped like Mitra. One worn sp. Catalina Is., 120 fixi* 

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



479«. ClathureUa (large). Sta. Barb., 20 fm. 



663. ClathureUa, 15 fm., Sta. Barb. 

 1852. ?aathHreUa, 4:0 {m. 

 1053. fDaphneUa, 60 fm. 



419, 426. Two species of shells resembling DaphneUa. 

 1055. ?Bela, 80 fm. 



423«. ManyeUa, 15 fm., Sta. Barb. 



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

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

 a young Vermetid.] 



463. " CanceUaria ? Tritonice, Sby. Agrees with Dr. Newcomb's specimen." S. 

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



81 7. CanceUaria. Fragment of a second species equally large. 

 1038. Sif/areftiii. 40 fm., dead. Cat. Is. 

 1050. LameUaria. 10 fm., Sta. Barbara. 

 (38o«, 404, 818.) Naticidce. 3 sp. 



101 



