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



Pericosmua lalus, Th. Fuchs, 1885, " Gliederung unt. Neog. Gebiete Mittelmeer," Zeit. deut. geol. 



Ges., xxxvii. p. 141. 

 Hemiaster latus, E. Requien, 1848, Cat. coquilles He de Corse, p. 96. 



Schizaster grateloupi, E. Sismonda, 1842, " Mon. Ech. foss. Piemonte," Mem. R. Ac. Set. Torino (2), 

 iv. p. 25, pi. ii. f. 1, 2. 

 ,, ,, E. Sismonda, 1842, Syn. meth. anim. invert pedem. foss., p. 13. 



,, ,, R. Hoernes, 1875, "Fauna Schliers Ottnang.," Jahrb. k. Jc. geol. ReicJis., xxv. 



p. 389. 

 ,, „ Th. Fuchs, 1877, "Geol. ubers. jung. Tertiarbild. Wiener Beckens," Zeit. deut. 



geol. Ges., xxix. p. 663. 

 Hemiaster ,, Agassiz and Desor, 1847, Cat. rais. Ann. Sci. Nat. Zool. (3), viii. p. 19. 



„ ,, E. Sismonda, 1847, Syn. meth. anim. invert, pedem. foss., ed. 2, p. 8. 



? Brissopsis ,, Ippolito Cafici, 1880, Boll. R. Com. geol. Italia, xi. p. 501. 



1 „ ,, L. Baldacci, 1886, "Descriz. geol. Sicilia," Mem. descr. Carta geol. Italia, 



i. p. 94. 



Distribution. — Malta — Globigerina Limestone. Corsica — Bonifacio ; St Florent. 

 Sicily (?) — Calcare di Siracusa (Tortonian). Italy — Colline de Turin (Helvetian). Nice. 

 Monte Titano (Aquitanian). Bologna ; Montese ; Serpentinosa molassa (Schlier). 

 Austria — Ottnang (Schlier). Madeira. 



Types.— kg. Casts, M. 23, T. 40. 



Remarks. — Owing to the imperfection of much of the material and of Sismonda's 

 figure of S. grateloupi, and the fact that Agassiz's cast of this species (T. 40) appears to 

 be missing from the set available for reference, I am only able to express a somewhat 

 doubtful opinion upon this species. M. Cotteau, who has given the synonymy with 

 care, has followed Desor in merging Sismonda's S. grateloupi in Pericosmus latus ; he, 

 however, omits any reference to Wright's Brissopsis grateloupi, so that he appears to 

 have suspected that Dr Wright's identification was erroneous. The Maltese specimen is 

 certainly distinct from P. latus, by the absence of the notch on the anterior margin. 



In the collection of the Geological Society there is a specimen labelled by Wright 

 as Pericosmus latus, and it agrees fairly well with the cast of Agassiz's type of that 

 species, and with M. Cotteau's careful description. It differs, however, from the speci- 

 mens identified by Dr Wright as Brissopsis (or Hemiaster) grateloupi by the pro- 

 minence of the anterior furrow, the conical form (when seen from the side), and the less- 

 marked divergence of the antero-lateral petals. The high posterior interradius of the B. 

 grateloupi, Wr., is the best character for their separation ; this species has a form much 

 like that of Micraster coranguinum, while P. latus, Wr., may be compared with the 

 form of Epiaster gibbus. It therefore follows either that Wright was wrong in referring 

 his specimens to S. grateloupi, Sism., or else MM. Desor and Cotteau were wrong in 

 making this a synonym of P. latus. As the English palaeontologist did not enjoy the 

 same opportunities for the study of this group as were possessed by these two eminent 

 Continental Echinologists, it seems wisest to accept their decision, especially as there are 

 differences between the Maltese specimens and Sismonda's figure. A new species, there- 

 fore, has to be made for the forms referred by Wright to Brissopsis grateloupi (Sism.). 



