ON MOLLTJRCA OF THE WEST COAST OF NORTH AMERICA. 557 



Spirxfflyphus alLidus, ?Cpr. Mazatlan, Reirjen. Operculum g et ?/, Maz. 

 Cat.' p. -Ml. = Bivonia albida, Cpr., Maz. Cat. p. 307. Operc. g is with- 

 out doubt of Spirofffyphu-s, and not of Bivonia, var. indentata. Operc. / 

 is truly congeneric, and perhaps conspecih'c. 



344 4. Vermetus (Thi/lcicjdu') contortus,C])Y.* Gulf Calif. Mas. Cum. 



Var. . repent (Tnylacodits). Gulf Ca if., on Mart/aritifera, Mns. Cam. 

 " This species is perhaps a state of V. (Petaloconchus) macrophraj- 

 ma." [Morch: uon Cpr.] f 



345 .. Va,r.p.favosa(Thu 7 acodus). Calif., on Crucibulum. M us. Cum. 

 . . Var. y. ' cantor tula ( Thylacodus), Gulf of California. 



,. .. Formal. ?Thyldcodus contortus, var. indent ata, Cpr. "Corre- 



sponds to forma 1, electrina, of Vermetus varians, D'Orb." 

 Var. 6\ indentata (Vermetus), [Morch, non Cpr.]. Sonsonate, on Spon- 

 dylus limbatus, Rve., non Shy. Oersted. 



346 . . Var. . corrodens ( Vermetus}. Is. Sibo (PQuibo), Spengler, on Pur- 



pur a lineata. 



359 20. Vermetus (?? Strebloceras) anellum, Morch. California, on Haliotis tttber- 

 culatus, live. [Not a Californian .Haliotis. The diagnosis, howeve**, 

 exactly accords with aCalifornian shell, which is perhaps the young- of' 

 S. squamiaerus. It has no resemblance to Slreolocerax, Cpr., P. Z. S. 

 1858, p. 440, which is a genuine Ccid.J 



860 21. Vermetus (Macrophragma) macrophragma. Mazatlan, &c.=Petaloconcht s 

 m. , C pr. Realej o, ' Oersted. 



362 24. Vermetus (Aletes) centiquadrus, Val. Puntarenas, Oersted + V. , effusuz, 



Val. (the same specimen). 

 . . . Var. a. maxima V. Punamensis, Chen. pi. 5. f. 1. Panama, C. B. Ad. ; 



Mazatlan, Melchers. 

 Var. /^. Punctis impress-is destituta,= V. Peronii, Val.^ 



363 . . Var. y. siphonata. Puntarenas, Oersted V. Peromi, Rouss. 



Var. d. tulipa. Gulf of California, on piece of black Pinna, Mus. Cum. 



[The Pinna niyrina is from the E. !]= V. tulipa, Rouss. 

 . , . . Var. e. Bridgesii. Panama, on Margaritifera, Mus. Cum. 



The conclusion of the paper is in P. Z. S. 1862, pp. 54-83. 



58 4. Bivonia sutilis, Morch. Central America, on Anomalocardia subimbricatu, 



Mus. Cum. 



. . . . Var. at. ?major. On Pinna, probably Central America, Mus. Bunker. 

 Var. /3. triquetra. Mazatlan, on valve of Placunanomia, Mus. Semper. 



Like B. triquetra, " var. typica." 

 70 8. Thylacodes cruciformis, Morch. California, on Crucibulum ? umbrella, 



Desh., var. Mus. Cum. Analogue of 7, T. Rusei, Morch, from the 



east coast. 

 Var. a., lumbricella. Voy. Ven. pi. 11. f. 2. California, crowded on 



Margaritifera. Mus. Cum. 

 .. .. Var. /3. erythosclera. CaL, on young Margaritifera. Mus. Cum. 



Very like Biv. Qttoyi, var. variegata. [This species is on shells from 



the Mexican, not the "Californian " fauna J 

 76 16. Thylacodes squamigera, C-pi\,= Aletes sg., Cpr., P.Z.S. 1856, p. 226. Sta. 



Barbara, Nutt. [Serpttlorbis, not Aletes } teste Cooper]. 



* Mr. Morch has not seen any laminae inside, but, from the 3-5 spiral lirse on the 

 columella, believes they will be found. The opercula supposed to belong to this species 

 (Maz. Cat. p. 311) Mr. M. thinks more probably those of Spiroglyphus albidus. He 

 states (erroneously) that the shell was not opened by the describer. 



f Morch supposes that Bivonia contorta, Cpr., may be the adult of Petaloconchus 

 macrophragma, and that both may be forms of Aletes centiquadrus. The nuclear por- 

 tions are, however, quite distinct, and the three shells appear, from beginning to end, as 

 far removed as any ordinary Vermetids can be from each other. 



J The writer doubts respecting this species, and think% the shell on which it is para- 

 sitical to be a Melo, and not Strombus galea, simply because named after Peron, who 

 did not visit this dislnuu 



43 



