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Description of the New Species and Varieties Jigured in Plates VIII. and IX. 

 By Mr. J. De Carle Sowerby. 



Dfsmopliyllum. This genus has been established by Ehrenberg, for a portion of those corals hitherto 



placed among the Turbinoliae. The type of the genus given by Ehrenberg is the Madrepora dianthus 



of Esper, the Caryophyllia dianthus of De Blainville. It is distinguished from Turbinolia by having 



been attached at the base ; and from the Cyathina of Ehrenberg {Caryophyllia cyathus), by the lamellae 



being fasciculated. 



PI. VIII. fig. 1. (a.) The termination of the plates magnified. (6.) Section of one segment. 

 Pcnnatula. This fossil resembles the bony axis of P. phosphorea, (Lam.), which occurs recent on the 



British coast, and has the same structure, and the form of the section also varies from square to round, 



in the same bone. 



PI. VIII. fig. 2. (a.) The natural size. (J.) Magnified. 

 Penfacriiius subbasaltiformis, (Miller). 



PI. VIII. fig. 3. (o.) The principal stem, (i.) The side arm, nearly cylindrical and extremely long. 

 Pentacrirtus Sowerhii, (Wetherell, MSS.). Joint* unequal in diameter, 5-lobed, with two obscure tubercles 



on each lobe of the larger joints. PI. VIII. fig. 4. 

 Pnlliceps} Posterior and lateral valves. PI. VIII. fig. 5. and PI. IX. fig. 2. 

 TelUna splendens. Ovate, convex, highly polished ; beaks central, small ; posterior extremity pointed, bent 



to the right. 



Gregarious, occurring in thousands in Septaria. PI. VIII. fig. 6. 

 Lucina Goodhalli. Subglobose, nearly smooth ; anterior slope concave ; lunette broad, flat, sunk ; pos- 

 terior slope convex, Avith one narrow and one broad groove on each side of it, meeting near the edge. 

 The young shell is sometimes very globose, at other times rather flattened. PI. VIII. fig. 7- 

 Venus tenuistriata. Oval, gibbose, marked with nearly close, concentric striae ; beaks prominent, nearest 



the anterior extremity ; lunette rather broad, pointed. PL VIII. fig. 8. 

 Area nitens. Transversely oblong, convex, smooth ; anterior portion small, rounded ; posterior subcunei- 



form ; front oblique ; shell thin. 



Some specimens have a few punctures, in which character they approach the next species. PI. VIII. 



fig. 9. 

 Area impolita. Transversely oblong, very convex, marked with longitudinal rows of punctures ; anterior 



portion small, rounded ; posterior rounded ; front parallel to the hinge line ; shell thin. 



It approaches A. cucullaris of Deshayes, vol. i. p. 206, pi. xxxiii. figs. 1, 2, 3 ; but differs slightly in 



form, as well as in the teeth being all transverse. PI. VIII. fig. 10. 

 Niicula Bowerbankii. Elliptical, convex, smooth externally, striated within ; anterior extremity obliquely 



truncated, the slope filled by a large, pointed, nearly flat lunette ; edge toothed ; impression of the 



abductor muscles shallow. PI. VIII. fig. 11. 

 Nucula Weiherellii. Suborbicular, transverse, gibbose, smooth ; extremities pointed ; beaks nearly central ; 



margin obtuse, edge toothed. 



The radiating structure of this Nucula, common to other species of the genus, is very conspicuous ; 



but the inner surface is not striated as in N. Bowerbankii. PI. VIII. fig. 12. 

 Nucula striata, var. (Lam., Ann. Mus., torn. vi. p. 126., tom. ix. pi. xviii. fig. 4 a., b. — Deshayes, vol. i. 



p. 236, pi. xlii. figs. 4, 5, 6.) This variety is less equilateral than in Lamark's and Deshayes' figures. 



PI. VIII. fig. 13. 

 Nucula compressa. Ovate, compressed, smooth; anterior portion very small ; lunette wanting. PI. VIII. fig. 14. 

 Avicula arcuata. Transversely ovate, arched, compressed, smooth, thin ; nearly twice as wide as long ; 



posterior ear large. PI. VIII. fig. 15. 

 Avicula papyracea. Nearly orbicular, much compressed ; concentrically waved ; ears small, unequal. 

 An extremely thin pearly shell, sometimes assembled in considerable masses. PI. VIII. fig. 16. 

 Deiitalium anceps. Slightly arched, longifridinally ribbed towards the apex ; one rib on each side of the 



arch prominent and sharp ; smooth towards the aperture, which is round. PI. VIII. fig. 17. 

 Scalaria undosa, var. (Min. Con. tab. Dlxxvii. fig. 4). This differs from the variety figured in Min. Con. 



only in having the costse less waved. PI. VIII. fig. 18. 

 Ovulum retusum. Egg-shaped, short, transversely striated. 



This differs from Ovulum ovum., the young state of which it very nearly resembles, in being shorter. 



We have not seen it with an inflected or thickened edge to the lip. PI. VIII. fig. 19. 

 Cytherina barbata. Transversely ovate, gibbose, smooth, with several spine-like processes at the extremi- 

 ties. PI. IX. fig. 1. 



