from the Loicer Greeiisand. 531 



short. But •when the description and figure of the Swiss test are 

 compared with specimens of tlie true C. faring donensis very obvious 

 differences between the forms become appai-ent. One of the most 

 readily recognized distinctions lies in tlie form of the test. Although 

 not more than four plates of C. faring donensis have been found 

 connected together, all the evidence points to its having been large 

 and tall, perhaps pyriform. De Loriol's specimen is quite small, and 

 remarkably compressed at both poles. The existence of from five to 

 six rows of granules in the widest parts of the ambulacra in the 

 Swiss specimen finds no counterpart in even the largest examples 

 from Faringdon. Although the absence or presence of crenelations 

 on the interambulacral tubercles has little systematic value, yet the 

 almost perfect smoothness of the platforms and parapets in de Loriol's 

 specimen, and the persistent, and often very apparent, crenelation 

 found in the species of the ' Sponge- gravel ', lend a fresh point of 

 contrast between the two forms. The 'granules tres fins' of the 

 scrobicular ring in the Swiss form do not correspond witli the 

 exceptionally large and spaced-out secondary tubercles from that 

 region in C. faringdonensis, while a similar difference is found in the 

 coarseness of the miliary granulation. On these grounds I feel 

 confident that the C. faringdonensis of de Loriol is a distinct species 

 from the C. faring done^uis of Wright, and should no longer bear the 

 same name. 



Almost twenty years later Lambert (Bull.Soc. geol. T" ranee, ser. in, 

 torn, XX, p. 39), describing the Echinoid fauna of the Aptien of 

 Grandpre, refers a Cidarid from that locality to C. faringdonensis ; or 

 rather, to the same species as that described by de Loriol. In the 

 latter identification he would seem to have been correct, as his figures 

 and descriptions agree in all essentials with those of de Loriol. It 

 is, therefore, unnecessary to repeat the reasons that cause me to 

 distinguish his species from the true C. faringdonensis. As a result 

 of his study of the test-structure, Lambert doubtfully referred his 

 species to Goniocidaris. Of the expediency or otherwise of this 

 generic determination there is no need to inquire here, save to remark 

 that sutural pits of the kind found in his species are well marked 

 in many Oolitic (e.g. C. marginata^ Goldf.) and Cretaceous (e.g. 

 C. sceptrifera, Mant.) species. But there is not the slightest trace of 

 such puts in the test fragments of C. faringdonensis ir ova the typical 

 locality, a fact which again emphasizes the difference between the 

 two forms. 



For this species, the C. faringdonensis of de Loriol (1873) and 

 the Goniocidaris faringdonensis of Lambert (1892), I propose the name 

 ' Cidaris'' testiplana, nom. nov., in reference to the extreme flattening 

 of its test. 



The only other reference of a fossil to C. faringdonensis, apart from 

 stratigraphical lists, is that by Stolitzka ( 1 873) in the Palceontugra'phita 

 Indica. Two very small fragments of poorly preserved radioles are 

 doubtfully referred to this species. Since the descriptions and 

 figures are as obscure as the specimens themselves, it is impossible 

 to speak definitely as to the coi'rectness of the determination. On 

 prima facie evidence, it would be very exceptional for a species 



