Luc 



CONCHIFERA. 



215 



Genus XL.— LUCiy! A— Bni>/uiere. 



Shell equivalve, inequilateral, usually orliicular, lenticular, 

 anil sub-dcpressod ; toetli variable, most commonly two minute 

 cardinal teeth divergent from the umbo, frequently nearly ob- 

 solete ; in one valve one lateral tooth on each side of the 

 umbo, and two on each side in the other ; tlio anterior lateral 

 ones being situate near the primary teeth, and the posterior 

 immediately behind the lijrament ; two muscular impressions 

 remote from each other, the anterior one generally extruded 

 backwards and downwards in the form of an elongated band ; 

 pallial impression destitute of a siuus ; ligament external, 

 elongated, and partly hidden by the inflected margins of the 

 valves when closed, consequently, the internal tendinous por- 

 tion is frequently sunk into a deep, elongated cavity, situate 

 between the teeth and hinge margin. 



1 . LuciNA DESPECTA. — The Despised Lucina, pi. LXXXIX. 

 fig. 5. 



L. despe/;tus. Phillips, Geo. York, I. pi. 9, fig. 8. 



Nearly orbicular ; beaks large and obtuse ; anterior side a 

 little smaller than the posterior ; surface smooth, with remote 

 lines of growth. 



The Great Oolite, Cloughton Wyke, and the Inferior 

 Oolite, Blue Wick. 



2. LlCINA LIRATA. 



L. lirata. Phillips, Geo. York, pi. C, fig. 11. 



Sub-orbicular, anterior side short, the line from the apex 

 being very slightly bent ; a longitudinal furrow close to the side 

 line ; posterior side rounded ; surface with many concentric, 

 narrow furrows, nearly straight, in the centre of the valves, 

 and turning abruptly up at both ends, those in the posterior 

 side bounded by the furrow. 



The Kelloways Rock, Scarborough. 



3. Lucina Goodiiallii. — Goodhall's Lucina, pi. LXXXIX. 

 figs. 1, 2, 3. 



L. Goodiiallii. Sowerby, Geo. Tr. 2d Ser. V. p. 13C, pi. 

 8, fig. 6. 



Sub-globose ; anterior side concave, posteriorly rounded ; 

 lunette broad, flat, and rather deejily sunk, meeting near the 

 edge, with a broad and a narrow groove on each side of it ; 

 surface nearly smooth. 



The London Clay, Highgate and Sheppy. 



4. Lucina globosa. — The Globular Lucina.p 1. LXXXIX. 

 fig. 17. 



L. globosa. Sowerby, Geo. Tr. 2d Ser. IV. p. 335, pi. 11, 



%-2. 



Nearly globular, anterior side straight for a short distance 

 below the beak ; posteriorly with a long flattened space ; 

 beaks sub-acute ; base mucii arcuated ; surface smooth, with 

 some shallow lines of growth, which are peculiarly waved near 

 the posterior margin. 



The Upper Greens.and, Kent and Sussex. 



.5. Lucina mites. — The Gentle Lucina, pi. LXXXIX. 

 fig. IG. 



L. initns. Sowerby, VI. p. 107, pi. 557, fig. 1. 



Circular, convex; lunette oval, and very deep; surface 

 covered with minute, longitudinal, numerous striso, crossed by 

 very regular lamina) ; cardinal teeth obscure, and destitute of 



a lateral tooth ; inside rough, but not punctated like many ol 

 its congeners. 



The London Clay, Barton and Ilighgate. 



G. Lucina gigantua. — The Gigantic Lucina, pi. LXXXIX. 

 fig. 33. 



L.gifjantea. Dcshayes, Coq. Foss. p. !)1, pi. 15, fs. 11, 12. 



Very broad, smooth, sometimes sub-striated, and internally 

 punctated ; hinge toothless, umbones large ; length frequently 

 upwards of three inches and a-half ; breadth three inches and 

 three quarters. 



The Loudon Clay, Barton. 



7. Lucina divabicata. — The Divergent Lucina, pi. 

 LXXXIX. fig. 25. 



L. divaricata. Lamarck, Env. de Paris, p. 244, Sowerby, 

 V. p. 18, pi. 417. 



Circular, gibbose ; surface with two sets of arcuated, ob- 

 lique, convergent striae, crossed by three or four deep, well- 

 marked lines of growth ; inside dull, and a little granulated ; 

 substance of the shell thick. 



The Mammiferous Crag, Bramerton, and the Red Crag, 

 Sutton and Barton. 



8. Lucina radula. — The Rasp Lucina, pi. LXXXIX. 

 fig. 19. 



L. radula. Brown's lUust. Conch. Brit, and Ireland. L. 

 antiquata. Sowerby, VI. p. 108, pi. 557, fig. 2. 



Circular, convex ; lunette lanceolate, flat ; surface with 

 many irregular, concentric, sharp laminw ; anterior side an- 

 gular ; substance of the shell moderately thick. 



The Red Crag, Sutton and Ramshot ; Mammiferous Crag, 

 Thorpe. 



9. Lucina crassa. — The Thick Lucina, pi. LXXXIX. 

 figs. 9, 10. 



L. crassa. Sowerby, VI. p. 108, pi. 557, fig. 3. 



Nearly circular, somewhat broader than long ; convex ; 

 beaks very small, 'superior margin obtuse ; lunette linear, 

 sunk ; surface with slightly elevated, concentric lamina; ; 

 valves thick. 



The Calcareous Grit, Cloughton Wyke, Yorkshire. 



10. Lucina orbicularis. — The Orbicul.ar Lucina, pi. 

 LXXXIX. figs. 11, 12. 



L. orbicularis. Sowerby, Geo. Tr. 2d Ser. p. 3+1, pi. 10", 

 fig. 13. 



Nearly orbicular ; a little elongated ; convex ; beaks small, 

 central, remote ; sides equal ; surface with numerous, divergent, 

 longitu<linal, frequently forked strias, and a few distant lines 

 of growth. 



The Groensand, Blackdown. 



n. Lucina pisum. — The Pea Lucina, pi. LXXXIX. fig. 13. 



/,. pisum. Sowerby, Geo. Trans. 2d Ser. IV. p. 341, pi. 

 16, fig. 14. 



Nearly orbicular ; beaks obtuse ; surface with fifteen or 

 more concentric, reflected ridges. 



The Greensand, Blackdown. 



12. Lucina Portlandica. — The Portland Lucina, pi. 

 LXXXIX. fig. 15. 



L. Portlandica. Sowerby, Geo. Tr. 2d Ser. p. 347, pi. 22, 

 fig. 12. 



Orbicular, compressed ; beaks nearly central and small ; sides 

 equal ; surface with fine, very regular, concentric stria;. 



