4 



BRITISH FOSSILS. 



planatus. This Bronn identifies with scutafa^ Lamarck ; but, though 

 evidently nearly allied, the depression is so great, and the anal furrow so 

 peculiarly shaped, that we cannot admit its identity. Bronn has also 

 referred with a query Goldfuss's figure of Nucleolites cordatus (pi. 43, 

 f. 9,) to it. That figure would serve as an excellent representation of 

 some of the varieties of clunicularis, but as it is a highly magnified 

 representation of a cretaceous fossil, it is probably distinct. The most 

 important works on fossil urchins remain to be cited, viz., those of 

 Agassiz. The first part of this eminent naturalist's work on the fossil 

 Echinodermata of Switzerland (1839) includes a monograph of the 

 Swiss Nucleolites (using the term in a very restricted sense), eight in 

 number, five of which are oolitic. Of these the first (^Nucleolites lati- 

 porus) appears to be a variety, more conical than usual, of N. dimidiatus, 

 Phillips. I have seen such a form in the collection of Mr. Tennant. 

 The second {Nucleolites micraulus) comes exceedingly near the same 

 species. The third {Nucleolites gracilis) is to my eye one of our com- 

 monest forms of N clunicularis. Nucleolites scutata, Lamarck, placed 

 fourth (distinguished from N scutatus, Goldfuss, which is unquestion- 

 ably dimidiatus), is our var. a in the form when passing into /3. The 

 fifth {Nucleolites major) is, judging from the figure, a slightly more 

 elongated and large variety of the same. The figures of all these are so 

 very excellent, that I do not hesitate in giving these opinions, especially 

 as the descriptions do not seem to contradict my conclusions. The later 

 work of Agassiz and Desor, " Catalogue Raisonne des Echinides " 

 (1847), is not so satisfactory. The first fossil Nucleolites there given is 

 scutatus, Lamarck, with reference to the figure in the " Echinodermes 

 Suisses." The second is " N clunicularis,^^ Phillips, the geology of 

 Yorkshire being the first citation ; its synonyms are " Nucleolites Gold- 

 fussii,^^ Desmoulins, and " Nucleolites Sowerbyi,^^ Defrance. The latter 

 reference we have already seen to be next to worthless ; the former name 

 is stated by M. Agassiz himself to have been given by Desmoulins to the 

 N. scutatus of Goldfuss (" Ech. Suisses," pi. 1, p. 45). Yet in this 

 catalogue the name of Goldfuss is quoted as a synonym of N. micraulus, 

 Agassiz, (on which I have already remarked ; but it appears to be dimi- 

 diatus, Phillips,) whilst dimidiatus is enumerated as a distinct species, 

 identical with Nucleolites paraplesius of Agassiz's " Catalogue Sys- 

 tematique." Then comes N. latiporus, Agassiz, with the note that it is 

 probably a variety of clunicularis ; whereas, in the " Echin. Suiss.," p. 43, 

 it is compared with Goldfussii, and a new species, N. Terquemi, said to 

 be near clunicularis also, whilst gracilis is retained as distinct. Further 

 on M. Desor has made a new species, " N. Thurmanni,^^ for a cornbrash 

 Nucleolites, " assez voisin du. N. latiporus,^^ which we had been already 

 told was itself "peut-etre une variete du A^. clunicularis^ We thus 



