FOSSIL ECHINOIDEA OE LAKE UKMI. 419 



"Weithof er * and by Borne t ; and the present specimen is doubt- 

 less referable to Perispliinctes curvicosta, Oppel, sp. J, a species 

 whicb Borne lias recorded and iigured {ojp. cit. p. 14, pi. i. fig. 1 ; 

 pi. iv. fig. 14) from rocks of Callovian age in the neighbourhood 

 of Maragha, whence the preseut specimen is believed to have 

 come. 



FOSSIL ECHINOIDEA. 



By J. W. Geeqoet, D.Sc, E.G.S. 



(Plate 28.) 



Me. Gunthee's collection of Ecbinoidea consists of five 

 specimens all of which belong to the genus Glypeaster. 

 According to Mr. Giinther, they are " said to have come from 

 Guverchin Kala, at the extreme northern end of Lake Urmi." 

 This locality is no doubt the same as the Guverchine Kalak 

 where the Hon. W. K, Loftus made a collection of fossils now 

 in the British Museum. 



Miocene Echinoidea from Lake Urmi have been described by 

 Abich §, who has recorded thence eight species of Clypeaster. 



1. Cltpeastee afli". impeeialis, Miclielin ||, 1861. (Plate 28. 



The most massive Clypeaster in the collection is unfortunately 

 so much broken on the margin and base that its positiye deter- 

 mination is impossible. But it clearly belongs to the group of 

 Clypeasters of which C. olisiponen&is, Mich.^, may be taken as 

 the type. Erom that species the Urmi echinid differs by having 



* K. Weithofer, " Ueber Jura und Kreide im uordwestlichen Persien " : 

 Sitzungsb. d. k.-k. Akad. Wissensch. Wien, Bd. xcviii. Abth. 1, Dec. 1889. 



t G. V. dem Porne, ' Der Jura am Ostufer des Urmiasees.' Inaugural 

 Dissertation. Halle, 1891. 



I A. Oppel, ' Die Juraformation,' p. 555 (1857). See also J. v. Siemiradzki, 

 " Monographische Beschreibung der Ammonitengattung P&risfhinctes " : 

 Palseontographica, Bd. slv. p. 96, 1898. 



§ H. Abich, " Ueber das Steinsalz und seine geologische Stellung im Euss- 

 ischen Armenian," M6m. Ac. Imp. Sci. St. Petersb. ser. 6, vol. ix. pt. 1, M6m. 

 Sei. Math.-Phys. vol. vii. 1859, pp. 111-114 ; and ' Geologische Forschungen in 

 den Kaukasischen Landern, Abth. ii. Geologie der Armenischen Hochlandes,' 

 i. 1882, pp. 223-225, 270-283. 



II H. Michelin, " Monographie des Olypeastres fossiles," Mem. Soc. G6ol. 

 France, ser. 2, vol. vii. p. 118, pi. xviii. figs. 2, a-d. 



^ Michelin, op, cit. p. 118, pLxs. figs. 1, a-f. 



