672 PKOF. J. W. GREGORY ON [Nov. I9II, 



of which specimens had been previously identified by Wright * as 

 Conoclypeus plagiosomus Ag. That species was founded by Agassiz 2 

 in the 'Catalogue Kaisonne' on specimens from the Molasse of 

 Southern France, and he then described it as 



' renflee, a bords tranchants, vemarquable par ses zones poriferes tres etroites.' 



Figures showing these characters have been given, as, for example, 

 by Laube 3 ; and they also show that the peristome has very pro- 

 jecting bourrelets. In the Maltese species the peristome is very 

 different from that of C. plagiosomus, as may be seen by comparison 

 of Laube's figure with that of H. hemisphericus* The resem- 

 blances, however, between the two species and the inversion of 

 the peristome led me to assume that the Maltese echinoid had small 

 jaws, though no fragments of them had been found. I accordingly 

 referred the species to Cotteau's genus Heteroclypeus. Dr. Stefanini 5 

 has called attention to the probably complete absence of jaws, and has 

 removed the species from the Conoclypeidae to the Cassidulidse, a 

 conclusion which seems to me correct; but Stefanini has gone further 

 than I can follow him in placing the species in Echinolampas. 

 The genus Echinolampas includes a large number of species, and it 

 seems to me undesirable to include this very distinct type in it. 



Echinolampas was founded by J. E. Gray 6 in 1825, but he did 

 not then distinctly select any one species as a type. Of the species 

 that he mentioned, E. oviformis was the best known and has been 

 practically adopted as the type. The Echinolampas from Malta 

 and Birlibah does not agree with this form of Echinolampad. It 

 is much nearer to the genus Palasolampas of Bell, with which it 

 agrees in its large .size, its circular or subcircular shape, the 

 extension of the petals to the margin of the test, and the subequal 

 length of the poriferous areas in each ambulacrum. The Echinoid 

 also agrees with Hypsoclypeus of Dr. A. Pomel, 7 in which Agassiz's 

 species plagiosomus was expressly included. The difference between 

 Palceolampas and Hypsoclypeus is perhaps not very important, but 

 it is accepted and perhaps overrated by M. Lambert : it depends 

 mainly on the structure of the peristome. Palasolampas, according 

 to Prof. J. F. Bell's diagnosis, has the bourrelets feebly developed, 8 



i T. Wright, 'Foss. Echinidea of Malta ' Q. J. G. S. vol. xx (1864) p. 483. 



2 L. Agassiz & Desor, ' Cat. Rais.' Ann. Sci. Nat. [Zool.] ser. 3, vol. vii (1847) 

 p. 168. 



3 ' Ech. (Esterr.-Ungar. Ob. Tert.' Abhandl. K-K. Geol. Eeichsanst. vol. v, 

 pt. 3 (1871) p. 67 & pi. xix, fig. 3. 



4 J. W. Gregory, ' Maltese Fossil Ech.' Trans. Roy. Soc. Eclin. vol. xxxvi, 

 pt. iii, No. 22 (1891) pi. i, fig. 11 b. 



5 ' Conoclipeidi & Oassidulidi Conoclipeiformi' Boll. Soc. Geol. Ital. 

 vol. xxvi (1907) p. 366 ; and ' Ech. Mioc. Malta nel Museo di Firenze ' ibid. 

 vol. xxvii (1908) p. 456. 



6 ' An Attempt to Divide the Echinida, or Sea-Eggs, into Natural Families,' 

 Ann. Phil. vol. xxvi (1825) p. 429. 



7 ' Classification Method ique & Genera des Echinides Vivants & Fossiles ' 

 Algiers, 1883, p. 63. 



8 ( On Palaolampas ' Proc. Zool. Soc. 1880, p. 48. 



