Messrs. Davidson & Morris on some species of Brachiopoda. 253 



Terebratula rugulosa, Morris. PI. XVIII. fig. 5, 5 a — c. 



Shell ovate ; valves nearly equally convex, somewhat truncated 

 anteriorly, dorsal valve more gibbose than the ventral, with a pro- 

 duced, rather obtuse and enlarged beak, but slightly recurved ; 

 foramen rather large ; deltidium wider than high, bordered by 

 elevated lateral ridges. Cardinal area smooth, lateral ridges 

 moderately distinct. The whole surface is covered by minute 

 rugae disposed as follows : those which cover the middle portion 

 of each valve are longitudinal and but little interrupted ; those on 

 the sides diverge and have a slight tendency to break into small 

 oblong tubercles, especially towards the beak of the dorsal valve ; 

 the intervening spaces are distinctly and thickly punctured 

 (fig- 5c). 



A fine series of this interesting species are in the collections of 

 Mr. Moore, Mr. Bunbury and Mr. Pratt. It is found in the chalk 

 marl at Chard, Somerset, and also occurs at Rouen. 



The following notice of the locality is communicated by Mr. 

 Moore. The bottom beds of the quarry are alternating layers of 

 chert and fine sand having a height of about twenty feet, but are 

 no doubt thicker, as the lower beds are not worked ; teeth of 

 fishes are occasionally found in it and a few corals ; above this is 

 a thin band of chalk marl, exceedingly fossiliferous ; it contains 

 several species of Ammonites, Nautilus, Hamites, Scaphites, Tur- 

 rilites ; Ceiithium, Pleurotomaria and Trochus ; Inoceramus, Area, 

 Cardium, Echini, &c, mostly in a beautiful state of preservation. 

 This bed is overlaid by the white chalk containing but few 



Terebratula spinulosa, Morris. PL XVIII. fig. 6, 6 a — c. 



Subovate, but with the broadest part rather behind the middle 

 and the front subtruncated ; dorsal valve rather more convex than 

 the ventral ; beak incurved, foramen tolerably large, the anterior 

 portion touching the apex of the ventral valve ; cardinal area con- 

 cave, minutely tuberculated, with distinct lateral ridges, diver- 

 ging almost at right angles from the foramen. Surface of both 

 valves covered with minute prickly tubercles (fig. 6 c) and fine 

 radiating strise ; lines of growth distinct. 



This is a very interesting and readily distinguished species, by 

 its form and peculiar structure. The prickly tubercles have a 

 tendency to a linear arrangement, and between them are nume- 

 rous small raised puncta, and fine or almost obsolete strise ; the 

 minutely tuberculated cardinal area is also a well-marked cha- 

 racter. The specimen figured is from the collection of A. Lewis, 

 Esq., of Wolverhampton, and Mr. Waterhouse has also pointed 

 out the existence of a species nearly resembling this, but in which 



