74 THE TERTIAEY FOSSIL ECHINOIDEA 



because of one very variable structural peculiarity, which is not of much physiological 



importance. 



In the well-known type Euspatangus rostratus, d'Archiac, from Kachh, no 

 peripetalous fasciole exists ; it has all the characters of a Maretia with a large anterior 

 notch. But in Sind, as will be noticed in our memoir on the Khirthar series, the 

 presence of a faint and short fasciole is evident. Hence we call these forms Eu&patangi, 

 and not Maretioe. 



The truly Nummulitic Echinoid fauna of Kachh has no affinities with those of 

 the Infra-Trap and Eanikot series of Sind ; it is to a considerable extent Egyptian 

 in its facies, but the species which give the idea of likeness are representative, not 

 identical. 



Only Echinolampas Vicaryi, Schizaster Baluchistanensis, and Euspatangus rostratus 

 have been previously observed in Indian Tertiaries ; they are species which were described 

 from Sind by MM. d'Archiac and Haime, and the first two are truly Nummulitic. 



Amongst the forms noticed by Grant and described in a very short memoir by 

 Sowerby, from Kachh*, one called by the latter (but not described) Galerites pulvi- 

 natus is an Amhlypygus ; another, called Clypeaster, is an Echinolampas, and probably 

 E. Vicaryi, d'Archiac ; a second Clypeaster, termed varians, but not described, only 

 figured, is one of the tall forms oilEchinolampas described in this memoir. Sowerby's 

 Spatangus acwminatus, Goldfuss, is Schizaster Baluchistanensis, d'Archiac. 



Memarks on the Forms from the Oligocene Series with Orbitoides. 



The number of species is very small, and Clypeaster predominates as a genus. 



There are four specimens of different species or varieties of the genus Clypeaster 

 in the collection of the Geological Society of London, which were noticed by MM. 

 d'Archiac and Haime and by Grant. Two are considered by the first named authors to 

 be varieties of Echinanthus profundus, and one is called by them Echinanthus Halaensis. 

 Capt. Grant and Sowerby appear to have been struck with the elongate form and 

 deep actinal surface of the fourth form, which, however, is in such a condition that we 

 do not propose to deal with it. It is necessary, however, to consider the first three 

 forms, which belong to the genus Clypeaster, Agassiz, and not to that of Echinanthus. 



Clypeaster peopuwdus, d'Archiac, sp. {op. cit. p. 207, plate xiii, fig. 14). 



In a form called by d'Archiac variety a, the length is greater than the breadth, 

 79 millim. to 62 millim., the margins are moderately thick but not tumid, and the 

 slope upwards of the rosette is sHght and to the apex. Irregularly pentagonal, the 

 margin is sharply rounded in front, incurved to the lateral ambulacra, then straight to 

 the truncated posterior lateral angle. The hinder margin is thinner than the front 

 and is slightly incurved. 



* Grant, « Geology of Cutch," Trans. Geol. See. ser. ii. vol. v. pt. 2, p. 327. 



