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



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

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



Hub. Sta. Barbara (Nuttall, Jewett} ; S. Pedro (Cooper] ; Cape 

 St. Lucas (Xantus}. 



This section differs from the typical Caffota as does Merce- 

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

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

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

 it resembles Dosinia ; in its ponderous growth, Pachydesina. 



110. Lazaria subquadrata. 



L. testa extus Carditce variegatce jun. simili ; pallida, castaneo tincta; 

 subquadrata, antice truncata, subregulariter ventricosa, dorsaliter 

 tumida ; costis radiantibus circ. xiv.-xvi., tumidis, nodosis, dia* 

 gonalibus majoribus ; interstitiis plus minusve insculptis : iutus, 

 valva dextra dente cardinali triangulari, inter duas fossas sito, haud 

 elongate ; dent. lat. a cardine separatis, ant. extante, post, obsolete, 

 calloso : v. sinistrali dent. card. ii. angustis, subsequalibus, radi- 

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

 datis. Long. '37, lat. -25, alt. '34. 



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

 S. Pedro (State Coll. no. 403) (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 carnea, epi- 

 dermide rufo-fusca, rujris increment! et Lncrustatione densissime 

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

 tres quadrantes totse latitudinis devectis ; area ligamentali curtis- 

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

 margine ventrali recto, vix propter byssum hiante ; postico lato, 

 antico angusto ; altitudine dorsaliter valde elevata, ventraliter 

 plane declivi, cuneiformi ; umbonibus trans marginem anticum per 

 sextantem totius longitudinis excurrentibus : intus, sub umbonibus 

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

 alt. -95. 



Hab. Sta. Barbara (Jewett) ; Monterey (Taylor). 



160. Pecten (? var.) aquisulcatus. 



if. testa P. ventricoso simili, sed tenuiore, minus ventricosa; costis 

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

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

 gerrato : testa juu. iiiterstitiis alte iiiscuh>tis. laminis concentricii 



280 



