256 Messrs. Davidson & Morris on some species of Brachiopoda. 



tolerably well with his description and figure ; the deltidium is 

 much smaller (according to his figure) than in our shell. 



Found rather abundantly in the lower greensand near Shank- 

 lin, Isle of Wight, by Dr. Fitton and myself (J. M.). Roemer's 

 specimens are from the Hilsthon of Elligser Brinkes. 



Terebratula flabellum, Defrance. PI. XIX. fig. 2 a — c. Diet, des 



Sci. Nat. vol. liii. p. 160, 1828. 



Shell somewhat transversely oval, costated, costa? round, im- 

 bricated, increasing in size but not in number towards the mar- 

 gin ; dorsal valve more convex than the ventral, with a produced 

 beak truncated by a rather large circular foramen ; cardinal area 

 concave, nearly smooth. Shell punctated. 



This species belongs to the Loricate of Von Buch, in which 

 the ribs of the ventral valve envelope those of the dorsal. It was 

 first described by Defrance, who cites it from the Calcaire k Po- 

 lypiers near Caen, Normandy ; in England it is rare. Mr. Wal- 

 ton and Mr. Pearce obtained it from the Bradford clay near 

 Bradford, and it also occurs in the same bed at Corsham, Wilts. 



Terebratula pygmcea, Morris. PI. XIX. fig. S «, b. 



Shell very small, of a somewhat hexagonal form, moderately 

 convex; beak acute, recurved; foramen small; area small, obtusely 

 triangular with distinct lateral ridges ; ventral valve with rounded 

 costse, which arising very near the cardinal area become much 

 larger towards the margin; interspaces deeply concave; dorsal 

 valve with furrows corresponding in number to the lobes of the 

 ventral valve ; front deeply sinuous, the central sinus by far the 

 largest. 



Locality : the Leptsena bed of the marlstone near Ilminster, 

 from Mr. Moore's collection. 



Associated with this species is another equally minute Tere- 

 bratula (PI. XIX. fig. 4 a — d) : it is of a rounded form, mode- 

 rately convex and perfectly smooth ; the beak small and scarcely 

 prominent. 



No specific name has been assigned to this species, as it pro- 

 bably may be a very young state even of a plicated shell. 



Terebratula maxillata. Sow. PI. XIX. fig. 5 a — g. 

 Shell subquadrangular, fully as broad as long ; valves nearly 

 equally convex ; beak produced, narrow and strongly recurved ; 

 foramen large, oblique ; deltidium obtusely triangular ; cardinal 

 area slightly depressed with obtuse lateral ridges ; ventral valve 

 with a mesial sinus and two broader lateral ones, corresponding 

 to the lobes of the dorsal valve, and which only extend one-third 

 inwards from the margin ; front strongly sinuated. 



