2 Dr. P. P. Carpenter on new Forms of MoUuaca 



callosa, Brit. Assoc. Kep. 1857 (from fragments) : non Venus cal- 

 losa (as of Conr.), Sow., Rve., Desh. 



Hab. Sta. Barbara {Nuttall, Jewett) ; S. Pedro {Cooper) ; Cape 

 St. Lucas {Xantus). 



This section differs from the ty|)ical Callisfie as does Merce- 

 naria from Venus. Whether the other pecuharities of the spe- 

 cies (redescribed by Reeve as Cijtherea nohilis) are coordinate, 

 cannot yet be stated, as it stands alone. In sculpture and colour 

 it resembles Dosinia ; in its ponderous growth, Pnchydesma. 



110. Lnzaria subquadrata. 



L. testa extns Carditce variegatce ]\m. simili ; pallida, castanpo tincta; 

 subquadrata, antice tiuiicata, subregulaiiter ventricosa, dorsaliter 

 tuinula ; costis radiantibus circ. xiv.-xvi., tuiiiidis, nodosis, dia« 

 gonalibus niajoribus ; inter:?titiis plus minusve insculptis : intus, 

 valva dextra dente cardinali triaiigulaii, inter duas fossas sito, baud 

 elongato ; dent. lat. a cardine sepaiatis, ant. extante, post, obsolete, 

 calloso : v. sinistiali dent. card. ii. augustis, subyequalibus, radi- 

 antibus; lat. ant. et post, extantibus : cicatr. adduct. subrotun- 

 datis. Long. 'Sr, lat. •2.>, alt. "34. 



Hab. Sta. Barbara {Jewett) ; Monterey, and along the coast to 

 S. Pedro (State Coll. no. 408) {Cooper). 



The outside of this remarkable little species is typically Car- 

 ditoid ; the hinge is intermediate between Lazaria and Cypri- 

 cardia, 



132. Modiola fornicata. 



M. testa curta, laevi, latiore, maxime fornicata; pallide earnea, epi- 

 dermide rufo-fusca, rugis incrementi et incru;tatione deusissinie 

 pilosa induta ; umbonibus maximis, spiralibus, antice torsis, per 

 tres quadrantes totse latitudinis devectis ; area ligamentali curtis- 

 sima, arcuata ; margine dorsali antice nullo, pnstice longo, arcuato; 

 margine ventrali recto, vix propter bys^um biante ; postico lato, 

 antico angusto ; altitudine dorsaliter valde elevata, ventraliter 

 plane declivi, cuneiformi ; umbonibus trans marginem anticum per 

 sextantem totius longitudinis excurrentibus : intus, sub umboniltus 

 excavata ; cicatr. adduct. ant. ventraliter sita. Long. 1*4, lat. "76, 

 alt. -95. 



Hab. Sta. Barbara {Jeirctt) ; Monterey {Taylor). 



160. Pecfen (? var.) cequisulcatus. 



J*, testa P. ventricosa simili, sed tenuiore, minus ventricosa ; costis 

 pluribus angustioribus xx.-xxi. ; interstitiis (prsecipue valva su- 

 periore) fere sequalibus ; auriculis magis productis, acutis ; sinv 

 eerrato : testa juii. interstitiis alte insculptis, laniinis ccucentricis 



280 



