— 302 - 



brevi, acute triangulari, rostriformi, postica producta et rotun- 

 data, margine ventrali medio sat arcuato, antice oblique ascen- 

 dente, subemarginato, dorsali utrinque parum declivi, umbonibus 

 callo refiexo occultis fere in ^3 anteriore sitis; valvulae utrinque 

 valde hiantes, hiatu antico permagno, subcordato, solidae, albae, 

 concentrice rugulosae, rugulis antice imbricatim crispatis, sulco 

 mediano transverso ab umbonibus radiante instructae, cardine 

 valde incrassato supine valvula accessoria singula, minima, sub- 

 triangulari obtecto, apophysi interna longa et curvata sublineari, 

 apice leviter dilatato. — Long. GO Mm. ISars. 



Pholas crispata Liiine ed. 12 p. 1111. — Forbes et Hanley I p. 114 



T. 4, F. 3-5 - Sow. III. Ind. T. 1. F. 11. - Jeffreys Br. 



Conch. III p. 112 T. 53, F. 1. — Locard Cat p. 367. - Sars 



Norv. p. 97. — de Kay Nevv York j) 247 T. 3-2, F. 506. - Gonld 



et Binney p. 30 F. 365. — Laniarck VI p. 46 

 Pholas bifrons da Costa Br. Conch. p. 242 T. 16, F. 5. 

 juv. = Ph. parva da Costa, Donovan, nec Pennant. 



Hab. litora oceani atlantici. 



5. Genus Pholadidea Leach. 



Diflfert a Gen. Pholas tosta in adultis antice callo omnino 

 clausa, postice appendice capuliformi subtestaceo munita, car- 

 dine subdentato, appendicibus dorsahbus 2 minimis in adultis 

 tantum praedito. 



Pholadidea papyraceaTurton. T. convexa, tenuis, in 

 junioribus antice cuneato-rostrata, medio constricta, antice liris 

 radiantibus squamoso-tuberculatis sculpta, postice fere laevis, 

 sordide alba; in adultis callo convexo irregulari antice clausa; 

 umbonibus ad 2/5 long. sitis, lamina cardinali dilatata, antice 

 super marginem producta, postice lamella triangulari dentiformi 

 munita, apophysi curvata, angusta; brevi; appendicibus interdum 

 unitis. — Long. ad 36 Mm. 



Pholas papyracea Tnrton Dith. p 2 T. 1, F. 1-4. 

 Pholadidea papyracea Forbes et Hwnley I p. 123 T. 5, F. 3-6, — 

 Sow. III. Tnd. T. 1, F. 12. - Jeffreys Br. Conch. III p. 116 

 T. 53, F. 2 - Locard Cat. p. 368. 

 Pholadidea Loscombiana Goodall mss. — Tiirton Conchol. Dict. 

 Pholadidea Goodalli Blainville, Pholadidoides anglicauus Gray in 

 Griffith Anim. Kingd., (ladmusia Solandevia Leach Mol. Gr. Brit. 

 fide Jeffreys. 



Hab. litora atlantica. 



2. Familia Gastrochaenidae* 



l. Genus Gastrochaena Spengler. 

 T. inclusa, valvis aequalibus, inaequilateralibus , maxime 



