Pholado.mya. 



CONCHIFERA. 



231 



10. Panop^a IpsvicieNsis. — The Ipswich Panopooa. 



P. Ipsciciensk. Sowerby, VII. p. 3, pi. 1 1, figs. 3, 4. 



Transversely elongated, sub-cylindrical ; somewhat com- 

 prossod ; thin ; posterior side truncated, and rounded ante- 

 riorly, with a slight protrusion of the edge ; beaks central ; 

 surface slightly wrinkled concentrically ; basal line nearly 

 straight. 



In the Coralline Crag, Ramshot, and at Ipswich. 



Genus LXVIII.— SOLEN.— Z»n»«Ms. 



Shell equivalve, transversely elongated ; sub-cylindrical, pro- 

 digiously inequilateral, umbones nearly terminal, situate close 

 to the anterior side, and gaping widely at both extremities ; 

 truncated or sub-truncated, sometimes rounded ; hinge linear, 

 with several small cardinal teeth, various in form, often acute 

 and recurved ; lateral teeth somewhat elongated and crooked ; 

 muscular impressions distant, tongue-shaped, the anterior one 

 joined a little behind the umbones ; the posterior one irregular 

 and sub-oval ; pallial impression elongated, straight, and 

 bifurcated behind ; ligament long and exterior ; external sur- 

 face covered with a thick horny epidermis. 



1. SoLEN siLiQUA. — The Pod Solen, pi. XCIV. fig. l-t. 



S. siliqua. Brown, 111. Rec. Couch. Brit. p. 112, pi. -16, 



fig-1. 



Very much elongated transversely, straight, sub-cylindrical ; 

 greatly inequilateral ; hinge situate at one side, with a single 

 thin, compressed, upright tooth in one valve, and an elongated, 

 remote, lateral laminas ; the opposite valve with two teeth, a 

 primary and a lateral one, corresponding to the lateral lamina; 

 opposite ; lower area striated transversely, with distant 

 lines of growth, both of which suddenly cross the area longi- 

 tudinally ; surface smooth. 



The Pleistocene Marine Formation, Clyde, and the Mammi- 

 ferous Crag, Bramertou. 



2. SoLKN Parisiensis. — The Parisian Solcn, pi. XCIV. f. 9. 

 Solen strigillatiis. Lamarck, An. du JIus. VII. p. *28, pi. 



43, fig. 5. Deshayes, Coq. Foss. p. 26, pi. 2, figs. 22, 23. 



Shell transversely oblong ovate, with the medial subsinus 

 somewhat rugose ; surface, towards the centre of the valves, 

 with obliquely longitudinal imbricated stri;o ; hinge with a 

 single tooth in one valve and two in the opposite one. 



Found in the London Clay, Bracklesham and Barton. 



3. Solen vaginalis. — The Vagina-like Solen, pi. XCIV. 

 fig. 18. 



iS. raginalii. Deshayes, Elem. Conch, p. 108, pi. 6, fig. 

 7. Coq. Foss. p. 25, pi. 2, figs. 20, 21. 



Shell linear, straight, the termination of the margin oblique ; 

 hinge with one triangular tooth. 



Found in the Lomlon Clay at Barton. 



4. SoLE.N Ensi-s.— The Sabre Solen, pi. XCIV. fig. 17. 



5. EiiiU. Brown, 111. Rec. Conch. Brit. p. 113, pi. 47, figs. 

 10, 10. 



Greatly lengthened transversely ; consiilerably arcuated 

 and truncated at both extremities ; hinge with a single car- 

 dinal tooth in one valve, locking between two in the opposite 

 one, which is provided with a strong, lateral, elevated, slightly 



recurved, cleft tooth, for the reception of the opposite simple 

 one, striated like <S'. sili<jua. 

 The Pleistocene Marine Formation, Ireland. 



5. Solen legumen. — The Pea-pod Solen, pi. XCIV. f. 13. 

 Solenocurtus legumen. Brown, 111. Rec. Con. Brit. \>. 1 13. 



pi. 47, figs. 8, 9, 9.* 



Gieatly elongated transversely, much compressed and thin ; 

 umbones placed to one side, but hardly marked ; hinge with 

 two small, erect, recurved, cardinal teeth in one valve, between 

 which an erect thin tooth in the opposite valve is locked ; 

 surface very smooth ; rounded at both sides. 



The Pleistocene Marino Formation, Ayr. 



6. Solen affinis. — The Allied Solen, pi. XCIV. fig. 1 6". 

 S. affinis. Sowerby, I. p. 15, pi. 3. 



Transversely elongated, arcuated, thin and much com- 

 pressed ; gaping at both sides ; hinge placed near one side ; 

 surface smooth. 



The London Clay, Highgate and Kingston. 



7. Solen pelagicus. — The Sea Solen, pi. XCIV. fig. 15. 

 <9. pelagicus. Portland, Geo. Rep. p. 441, pi. 36, fig. 4. 

 Transversely elongated ; straight, lancet-shaped, rounded at 



both extremities ; a small beak near the broader end, pro- 

 ducing a bend under the margin ; a keel-like ridge from the 

 beak to the posterior margin. 

 The Carboniferous Limestone, Clogher, Tyrone. 



Genus LXIX.— PHGLADOMYA.— y. Sowerby. 5 



Shell transverse, inequilateral, equivalve, ventricose, very 

 thin and hyaline ; anterior side more or less elongated and 

 gaping ; posterior side sometimes very short, rounded ; upper 

 edge slightly gaping ; hinge with a small, rather elongated, 

 triangular pit, and a marginal lamina in each valve ; to the 

 outer surface of which is attached a somewhat short external 

 ligament ; inside pearlaceous ; two indistinct muscular impres- 

 sions ; muscular impression of the mantle nearly obsolete, and 

 with a largo sinus. 



1. Pholauomya margaritacea. — The Pearly Pholado- 

 mya, pi. LXXX. figs. 8, 9. 



Cardita margaritacea. Sowerby, III. p. 175, pi. 297, f. 2. 



Transversely ovate, its widtii exceeding its length ; in- 

 flated ; anterior side a little produced, provided with an ob- 

 scure, longitudinal keel, and several small ridges, concentri- 

 cally and irregularly undulated ; beaks prominent, greatly in- 

 curved, and with a considerable hollow beneath them. 



London Clay, Bogiior ; Richmond, Isle of Wight, and 

 Brentford. 



2. Pholadomya prodocta. — The Produced Pholadomya, 

 pi. XCV. fig. 8. 



Cardita (?) producta. Sowerby, III. p. 219, pi. 197, f. 1. 



Gibboso, transversely oblong, being about a third v/idcr 

 tli.an long ; surface with six or seven longitudinal ridges, which 

 are higher towards their posterior half; anterior side pro- 

 duced and plain ; beaks rather prominent. 



Lias, Batii, and Peterborough. 



3. PiioLADourA OBTUSA. — The Obtuse Pholadomya, pi. 

 XCV. fig. 6. 



