598 MR J. W. GREGORY ON THE MALTESE FOSSIL ECHINOIDEA. 



named Echinodiscus subrotundus, but he included in the same species specimens from 

 Fiance and Switzerland ; thus he gave as references paragraph 229 of Davila's Catalogue,* 

 in which specimens from Aunis with long petals are expressly mentioned, and Andrea's 

 figure t which is however of a Maltese specimen. Lamarck followed Leske, and applied 

 his name to the common French species. Marcelles de Serres was the first to notice 

 the differences between the specimens from the " Calcairc a asteries " and those of higher 

 horizons : he separated the former as a new species S. striatula, keeping the name S. sub- 

 rotunda for the long-petalled forms from the Faluns de Leognan. This was rather 

 unfortunate, as had Marcelles de Serres examined Leske's figures, he would have seen 

 that it was the species from the higher horizon that required a new name, and that his 

 S. striatula was identical with the specimen figured by Leske as E. subrotunda. If we 

 take Leske's figure as the type, then the use of the names of the French species should 

 be reversed ; this, however, would lead to sad confusion, as they are both important 

 zonal fossils. But the wisely-drafted rules of the British Association fortunately enable 

 such a step to be avoided, for as Leske included both species in his name, it was open to 

 Marcelles de Serres to decide for which one the old name should be retained. No 

 doubt great subsequent confusion would have been avoided had de Serres retained 

 S. subrotunda for the species originally figured as such, but this need not entail any 

 alteration in the customary interpretation, except that the Maltese species must be 

 known in future as S. striatula. The range of the two species has been discussed with 

 care by Tournouer.J 



Genus Heteroclypeus, Cotteau, 1891. 

 Species l. Heteroclypeus hemisphsericus, n. sp. Plate I. fig. lia-c. 



Diagnosis. — Test large and massive, nearly circular, the antero-posterior diameter 

 very slightly exceeding the transverse. The base is flat, the sides curve gently to the 

 depressed upper surface. In some cases a tendency to become conical. 



Ambulacra : Poriferous zones narrow, but the petals extend to the margin, flush with 

 the test. 



Apical system central. 



Epistroma: Small granules uniformly scattered over the whole test; each of the 

 small tubercles set in a small scrobicule. 



Peristome a little before the centre, transverse, surrounded by a prominent floscelle ; 

 the bourrelets are high and strong ; the doubled pores in the phyllodes distinct. 



PerignatJiic girdle high. 



Anus inframarginal, transverse. 



* Catalogue systematique et raisonne" des Curiosite's, iii., Paris, 1767, p. 184. 



t Andrea, Briefe aus der Schweiz nach Hannover geschreiben, ed. 2, 1776, p. 40, tab. v. f. g. 



I " Recensement Ecbinod. du Calc. a Asteries," Actes Soc. Linn. Bordeaux, xxvii., 1869, pp. 278-282. 



