86 Mr. J. Morris's Palaontological Notes. 



Thecidea Wetherellii. PI. IV. fig. 1-3. 



T. testa parva, tenui, irregularis sublsevigata ; valva inferiori tri- 

 angulari vel pentagonali, interne striata ; area brevissima, del- 

 tidio magno ; valva superiori operculiformi planulata vel sub- 

 convexa. 



A small^ thin and smooth shell, nearly as wide as long, of a 

 pentagonal form, and triangular towards the cardinal region, 

 rounded laterally and straight on the anterior margin. 



The inferior valve is attached by nearly the whole of its sur- 

 face, the edges only being slightly elevated, and the beak de- 

 pressed ; the cardinal area is small, and chiefly occupied by a 

 large triangular, rather elongated deltidium ; besides the cardinal 

 teeth, the interior beneath the deltidium is furnished with three 

 laminar processes, of which the central one is generally the long- 

 est and most elevated ; the inner surface of this valve is marked 

 by longitudinal granular strise (fig. 3). The smaller valve is flat 

 or slightly convex, and has a large apophysary system, divided 

 on each side in a deep, arched or reniform sinus ; the cardinal 

 process is large, and the margin of the valve is minutely gra- 

 nulated. 



This species presents considerable resemblance in its general 

 form to the recent T. mediterranea, and more to the T. triangu- 

 laris, figured by Mr. Davidson, from the Inferior Oolite and Lias 

 of England, and which is also found in the same formations as 

 well as in the Great Oolite of Normandy. The apophysary system 

 differs from that of the recent species in being more simple and 

 less flexuous, and approaches that of T. hippocrepis, Goldf. ; but 

 the dissepiment is not so broad as in that species. It is fre- 

 quently attached to the shells of Ananchytes, Spatangus, and 

 Inoceramus from the Upper Chalk of Northfleet, Kent, and has 

 been dedicated to N. T. Wetherell, Esq., who has succeeded in 

 preserving this and many other minute and rare organisms from 

 the same locality. 



Talpina. 



Under this name M. von Hagenow has arranged certain pro- 

 blematical branching bodies which traverse the spathose guard 

 of the Belemnite, and whose position in the animal kingdom has 

 not been defined, whether as belonging to the Annelides or to the 

 boring Sponges. M. Hagenow remarks, that only the cylindric 

 thread-like channels are left, by which the Belemnite has been 

 perforated, most likely after the death of the animal, and perhaps 

 only after the outer shelly substance was decayed, but evidently 

 before the process of petrifaction commenced. These channels are 

 close under the surface of the Belemnite, either simple or branched, 

 and frequently show openings at the surface, and are filled with 



