ON MOLLirSCA OF THE WEST COAST OF NORTH AMERICA. 557 



P?;e. Sp. 



oJ:3 8. Spiroglyphus albidus, ?Cpr. Mazatlan, Heir/en. Operoiilum g et ?/, Mp.z. 

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

 out doubt of Spiruglyphus, and not of Bivonia, var. indentata. Operc. / 

 is truly congeneric, and perhaps conspecittc. 



344 4. VermHus [Thglacodu i) coniortus, C^r.* Gulf Calif. Mus. Cum. 



Yen. n. repens(^Thylacodiii). GuU idU., on Margaritif era, 'Mas.Gw.v. 

 " This species is perhaps a state of V. (^I'etaloconchus) macrophnrj- 

 ma." [Morch: non Cpr.]t 



345 ,. Yav. ^.favosa (Tht/lacodus). CsXit, on Crucilulum. Mus. Cum. 

 ., ., Y&r. y. contortula iThylacodus). Gulf of California. 



.. .. Formal. fThylacudus contoHiis, var. indeiitdta, Op\-. "Corre- 



spond? to forma 1, electrina, of Vermet>.i.i tarians, D'Orb." 

 ., .. Var. 8. indentata (Vermetus), []MOTch,non Cpr.]. Sonsouate, on Sjion- 

 dyliis limbatus, Rve., non Shy. Oersted. 



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



pura lineata. 

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

 culatus, "Rve. [Not a Californian Haliotis. The diagnosis, howfm^i-, 

 exactly accords with a Californian shell, which is perhaps the young r.f 

 S. squamigerus. It has no resemblance to Strebtoceran, Cpr., P. Z. y. 

 1858, p. 440, which is a genuine Ceecid.] 

 860 21. Vermetus {Macrophragtna) macrophrag7na. Mazatlan, &c.=P(3i!a/oeo«c,'i(.s 



m., Cpr. Realejo, Oersted. 

 362 24. Vermetus (Aletes) centiquadrus, Val. Puntarenas, Oersted -\- V. effustis, 



Val. (the same specimen). 

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

 Mazatlan, Melchers. 

 Var. /3. Panctis impressis destituta,= V. Peronii, Val.J 

 3G3 . . Var. y. siphonata. Puntarenas, Oersted= V. Peronii, Rouss. 



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

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

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



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



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



Mus. Cum. 

 . . . . Var. a.. ?major. On Pinna, probably Central America, Mus. Dunker. 

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



Like B. triquetra, " var. typicd." 

 70 8. Thylacodes cruciformis, Morch. California, on Crucibuhim fiimbrella, 



De.sh., var. Mua. Cum. Analogue of 7, T. Rdsei, Miirch, from the 



east coast. . 

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



Margaritifei-a. Mus. Cum. 

 ,. .. Var. j3. erythosclera. Cal., on young Margaritifera. Mus. Cum. 



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



the Mexican, not the "Californian" faunaj 

 76 16. TAi/Zoco&s sywam^yera, Cpr., =vifc<es sy., Cpr., P.Z.S. 1856, p. 226. Sta. 



Barbara, Nutt. [Serpulorbis, not Aletes, teste Coopei-^- 



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

 columella, believes tliey will be found. The operonla supposed to belong to this species 

 (Maz. Cat. p. 311) Mr. M. thinks more probably those of Spiroglyplius albidm. He 

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



^ Morch supposes that Bivonia contorta, Cpr., may be the adult of Petaloconclms 

 macropTi/ragma, and that both may be forms of Aletes centiquadrus. The nuclear por- 

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

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



X The writer doubts respecting this species, and thinks the shell on which it is para- 

 sitical to be a Melo, and uot Stromius galea, simply because named after Peron, who 

 did not visit this distnei,. 



43 



