202 



23. DiPLODONTA ORBELLA, Gould. 



Lucina orbella, Gould, p. 22. pi. 15. f. 3. 



? = Biplodonta semiaspera, var. : v. B.M. Maz. Cat. p. 102. 

 no. 1.50. 



Hab. Santa Barbara {Jeioett). Mus. Gould. 



24. Cyrena Mkxicana, var. altilis, Gould. 



Cyrena altilis, Gould, p. 27. pi. 16. f . 5 ; vide B.M. Maz. Cat. 

 p. 115, no. 165. 



Hab. Mazatlan. Mus. Gould, Brit. 



25. Anodon cicoNiA, Gould, p. 29; B.M. Maz. Cat. p. 117. 

 no. 166. 



26. Mytilus glomeratus, Gould, p. 29. pi. 16. f. 8. 

 Hab. San Francisco {Maj. Rich.). Mus. Gould. 



27. MODIOLA NITENS, n. 8. 



M. t. tenui, gibbosa, maxime elongata, striis incrementi cotispi- 

 cuis ; epidermide olivaceo-cornea nitente induta ; parte antica 

 angusta, umbonibus obtusis, spiralibus, terminalibus ; parte 

 postica maxime producta ; angulo diagonali indistincto, ma.vime 

 tumente ; marginibus, ventrali incurvato, dorsali plūs minusve 

 angulato ; intus purpurea, parte ventrali albida, translucida ; 

 linea cardinali tenui, edentula. 



Long. 1-05, lat. •2--45, alt. -38. 



Hab. California, teste Gould. Mus. suo. 



Has the shape of Mytilus multiformis (B.M. Maz. Cat.), the in- 

 ternal colouring of M. Braziliensis, and a glossy epidermis over the 

 irregular lines of growth of a lustrous olivaceous hue. 



28. LiTHOPHAGUS FALCATUS, Gould. 



Lithodomus falcatus, Gould, Proc. B. N. H. S. Nov. 1851 ; Mex. 

 &c. p. 30.pl. 16. f. 9. 



=i. črrMwm, Phil. (New Zealand). Mus. Cum. 



I do not know which name has precedence ; but a comparison of 

 types of these most remarkable shells affords no opportunity for 

 separating the species, widely as their habitats are removed. 



Hab. Monterey {Rich.). Mus. Gould. 



29. Byssoarca pernoides, n. s. 



B. t. subquadrata, planata, albida, epidermide spongiosa fugca 

 induta; striis eocilibus radiantibus, confertissimis ; minutissime 

 tuberculosis ; umbonibus obtusis, antice sitis, area parva ; 

 intus linea dentium tnaxime arcuata, dentibus extremis validis, 

 interioribus parvis, confertis, ąuadratis ; cicatr. muse. rotun- 

 datis, politis ; pagina interna, intra lineam pallii, radiatim 

 striata ; margine simplici ; ligamento fossis quadratis minutis 



