﻿UNDULA^'iVE. 73 



but with some irregularity. The lines of growth are conspicuous over the greater 

 portion of the shell. Portions of the epidermal granulated tegument are preserved, 

 and have the lines of granules larger than is usual in the Undulates or the Clavellata. 

 Our figure exemplifies a specimen, the posteal extremity of which is somewhat defective 

 from disappearance of the test. 



Locality and History. Our specimen is from the Portland Oolite of Tisbury; Mr. 

 Cunnington has also obtained the species in the same formation near to Devizes ; at both 

 localities it ranks as one of the most rare Testacea in the formation. Allusion may here 

 be made to T. radiata, Benett, the absence of which in this Monograph as a recognised 

 species requires some explanation. 



In the year 1831, Miss Etherelda Benett, of Warminster, published a small folio 

 volume, intended as an illustrated catalogue of Wiltshire fossils ; plate xviii, fig. 3, 

 of that work, represents Triyonia radiata from the Portland Limestone of Tisbury ; the 

 figures generally in IMiss Benett's work are carefully drawn, it may therefore be assumed 

 that the deficiencies in the Trigonia represent the defective condition of the specimen. 

 The general aspect seems to indicate flattening or compression ; the area has no clearly 

 defined features ; the marginal carina has some indistinct tubercles; the rows of varices which 

 pass downwards from the carina are more clearly expressed, and appear to be obtusely 

 nodose ; there are also some partially preserved tubercles upon the pallial portion of the 

 valve near to the lower border ; all else is left to the imagination. The type specimen 

 was removed to the Philadelphian Museum, with the whole of Miss Benett's collection, at 

 the decease of that lady ; but, judging from the figure, the possession of the specimen 

 would have added but little to our knowledge of the species, and no second British 

 example recognised as T. radiata is known. 



In the year 1865 M. Munier-Chalmas figured and described under the name of 

 T. Ferryi {' Bull. Soc. Linn, de Normandie,' vol. ix), a Trigonia which in the general 

 characters of its varices possesses a considerable resemblance to the figure given by Miss 

 Benett ; the anteal portion of the valve is represented as devoid of ornamentation, but as 

 this, in common with the other figures upon the same plate, is reduced in size, we are 

 the less able to judge of the actual condition of the specimen ; he also described in the 

 memoir accompanying the plate an allied Trigonia from the same formation, in the 

 vicinity of Boulogne, under the name of T. Carrei, but of this no figure was given. 



In the following year appeared the almost simultaneous pubhcation of Memoirs on the 

 Portland formation of Boulogne by Professor Hebert, and Messieurs de Loriol and 

 Pellat, each of these palseontologists discovered the apparent identity of T. Ferryi with 

 T. radiata, and the last-named authors figured a very perfect example of T. Carrei, and 

 another of T. radiata; the latter form is, however, apparently defective, the anteal 

 half of the valve being separated from the other portion with varices by a line of fracture, 

 which apparently indicates the absence of the test upon the anteal portion of the valve, 

 the varices of which end abruptly at the line of fracture. Several large clavellated 



