Terebratula. 



MOLLUSCA. 



139 



Carboniferous Linicstono, Ireland ; Devonian Shales, 

 Plymouth ami Newton. 



9-1. Terebratula dimidiata. — The Divided Terebratula, 

 pi. LA'L* !!■:. 22, 23. 



T. dhnid'mta. Soworby, III. p. 138, pi. 277, fig. 5. 



Transversely obovato, and subcompressed, and wider than 



long ; beak straight, a little produced ; upper valve convex ; 



surface with about thirty plaits, the half of which on one side 



elevated, producing the appearance of being medially divided. 



Its straight beak aiid greater width than length distinguish it from 

 7. inconstant. 



Greensand, Haldon. 



!15. Terebratula pectita. — The Little-Comb Terebra- 

 tula, pi. LYI. fig. 88, 89. 



T. pectita. Sowerby, II. p. 87, pi. 138, fig. 1. Brongniart 

 Env. de Paris, pi. 9, fig. 8. 



Siiborbicular ; gibboso ; with a medial hollow, extending 

 from the beaks to the base ; beak considerably produced ami 

 slightly incurved ; surface with very numerous longitudinal 

 rounded stria3, which are frecjuently furcated towards the 

 base. 



Under Greensand, "Warminster and Swanage Bay. 



96. Terebratula seminula. — The Little Seed Terebra- 

 tula, pi. LV.* fig. 6, 7. 



T. seminula. Phillips, II. p. 222, pi. 12, fig. 21, 22, 23. 



Nearly orbicular ; beak rather pointed, perforation very 

 small ; surface smooth, with one lateral plait. 



Carboniferous Limestone, Bolland. 



98. Terebratula antiquata. — The Ancient Terebratula, 

 pi. LV.* fig. 17, 18. 



T. antiquata. Phillips, II. p. 223, pi, 11, fig. 20. 



Oblong-oval, beak prominent ; hinge line nearly parallel ; 

 base rounded ; upper valve plane, with two ribs emanating from 

 the combs, and divergent ; lower valve convex ; surface smooth. 



Carboniferous Limestone, Bolland. 



99. Terebratula pexTjEdra. — The Pentagonal Terebra- 

 tula, pi. LV.*fig. 19, 20. 



T. pentcedra. Phillips, II. p. 221, pi. 12, fig. 3. 

 Pentagonal ; compressed ; beak rather large, the perforation 

 minute ; front and sides emarginate ; surface undulated. 

 Carboniferous Limestone, Bolland. 



100. Terebratula lentifor.mis. — The Lens-shaped 

 Terebratula, pi. LV.. fig. 23, 24. 



T. lentifortnis. "Woodward, Geo. Nor. pi. 6, fig. 11. 

 Nearly orbicular, slightly lenticular ; beak small, perforation 

 minute ; surface smooth. 

 tapper Chalk, Norwich. 



101. Terebratula riiomboidea. — The Rhomboidal Tere- 

 bratula, pi. LV.* fig. 29, 30, 38, 39. 



T. rhomboidcB. Phillips, II. j). 222, pi. 12, fig. 18, 19, 20. 

 lb: Pall. Foss. p. 88, pi. 3J, fig. 1 J8. 



Subrhomboidal ; beak largo and rounded, perforation minute, 

 destitute of lateral plaits. 

 Carboniferous Limestone, Bolland and "V\''hitehall. 



102. Terebratula obsoleta. — The Obsolete Terebra- 

 tula, pi. LA'I. fig. 90. 



T. obsoleta. Sowerby, I. p. 192, pi. 83, fig. 7. 



Almost orbicular, gibbose ; centre of the front a little elevated 

 by seven jdaits ; beak produced ; sides with from seven to 

 eleven sharp plaits ; depth about two-thirds the length. 



103. Terebratula pentagonalis. — ThePentagonal Tere- 

 bratula, pi. LV.* fig. 14, 15. 



T. penlajonalis. Phillips, I. p. 91, pi. 1, fig. 17. T. pcn- 

 tangidata. AVoodward, Geo. Nor. p. 54, pi. G, fig. 10. 



Pentagonal ; beak but slightly produced ; sides nearly paral- 

 lel ; a shallow mesial furrow, extending from the beuk of the 

 larger valve to the base ; sm.n.ll valve depressed in the centre ; 

 base concave in the centre ; surface smooth. 



Under Chalk, Dane's Dike and Hartford. Red Chalk, 

 Hunstanton. 



104. Terebratula lineolata. — The Lined Terebratula, 

 pi. LV.» fig. 32. 



T. lineolata. Phillip-s, I. p. 95, pi. 2, fig. 27. 



Subquadrate, beak considerably produced ; slightly incurved, 

 sides moderately rounded ; base with a broad central projec- 

 tion ; surface with rather wide divergent strias or linea- 

 tions. 



Speeton Clay, Speeton and Knapton. 



105. Terebratula convexa. — The Convex Terebratula, 

 pi. LV.» fig. 50, 51. • 



T. convexa. Sowerby, Geo. Tr., 2d Ser. IV. p. 339, pi. 

 14, fig. 12. 



Subtriangular, sacculiform ; beak large, considerably pro- 

 duced and slightly incurved ; angles rounded ; valves regularly 

 convex ; front a little elevated ; surface with numerous diver- 

 gent slightly rounded ribs. 



Lower Greensand,. near Hythe. 



106. Terebratula elegams. — The Elegant Terebratula, 

 pi. LV.* fig. 75, 76. 



T. elegans. Sowerby, Geo. Trans. 2d Ser. IV. p. 338, pi. 

 14, fig. 11. 



Transversely obovate, or nearly orbicular ; beak prominent, 

 acute, almost straight ; front a little elevated and straight 

 surface with numerous sharp, divergent, narrow ribs. 



Lower Greensand, Lympne, Kent. 



1 07. Terebratula faba. — The Bean-shaped Terebratula, 

 pi. LIV.* fig. 20, 21. 



T. faba. Sowerby, Geo. Tr. 2d Ser. IV. p. 338, pi. 14, 

 fig 10. 



Longitudinally elliptical, narrow, gibbose ; beak short but 

 prominent , front concave, but not elevated ; surface smooth. 



Lower Greensand, near Folkstone. 



108. Terebratula parvirostris. — The Short-Beaked 

 Terebratula, pi. LV.* fig. 83, 84. 



T. parvirostris. Sowerby, Geo. Tr. 2d Ser. IV. p. 339, pi. 

 14, fig. 13. 



Slightly tetrahedral, orbicular ; beak small and acute; sides 

 angular, and slightly produced ; surface with numerous angular 

 divergent ribs, eight or nine of them considerably elevated 

 in front. 



Lower Greensand, East of Shanklin. 



109. Terebratula dilatata. — The Enlarging Tere- 

 bratula, pi. LVI. fig. 70, 71. 



T. dilatata. Sowerby, Geo. Trans. 2d Ser. IV. p. 343, pi. 

 18, fig. 2. 



Transversely elliptical, imperfectly trilobate ; central lobe 

 elevated ; beak of the larger valve short and large, with the 

 point considerably incurved and sharp ; surface with about 

 fifty sharp divergent plaits, giving the whole external margin 

 a serrated appearance. 



