424 DR. J. W. GEEGOET ON THE 



The main difference between the three specimens of C. Martini 

 from Guverchin Kala is in the tumidity of the ambulacra. This 

 character is least developed in the more broken of Mr. Giinther's 

 specimens, and most pronounced in the specimen in the Loftus 

 Collection, which presents an approach to C. crassicostatus, 

 Agassiz.* 



Among the specimens of Clypeaster from the Indian Cainozoic 

 this species is closest to G.faloriensis, Dune. & Sladent, which has 

 the same long open petals and depressed test ; but in the Indian 

 specimen the margin is tumid and the height of the test less. 



EOSSIL COEALS. 



By J. W. Geegoet, D.Sc, F.G.S. 



(Plate 28.) 



The fossil corals in Mr. Giinther's collection from Lake Urmi 

 number 19 specimens, of which 6 came from the conglomerates 

 at Seir, 6 or 8 miles west from the lake, and 8 came from 

 the island of Koyun Daghi ; the exact locality of the remainder 

 is not stated. One of the specimens from Seir and one from 

 Koyun Daghi are indeterminable. The rest may be divided 

 among eight species, which have been previously recorded or 

 described from Lake Urmi by Abich J. The corals are Miocene, 

 and mainly Helvetian in affinities. The Ostrea-Virleti beds 

 which yield Tliamnarcea poJymorpha are shown by the Mollusca, 

 according to Mr. E. B. Newton, to be Tortonian in age. 



1. Oebicella Deeeancei {Edwards Sf Saime), 1849. 



One of the best-preserved corals in Mr. Giinther's collection 

 is a fragment of a flat tabular corallum, about 15 mm. thick, in 

 which the septa number three orders with rarely a rudimentary 

 septum of the fourth order ; the septa are thick near the margin, 

 but have no paliform lobes ; the columella is parietal, but strong 



* Michelin, op. cit. p. 115, pi. XTii. figs. 1, a-f. 



t Duncan & Sladen, " Fossil Echinoidea of Kachh and Kattywar," Pal. 

 Indica, ser. XIV. vol. i. pt. 4, 1883, p. 60, pi. xii. fig. 15. 



I H. Abich, 1859, " Ueber das Steinsalz und seine geologische Stellung iin 

 Eussischen Armenien," Mem. Ac. Imp. Sci. St. Petersb. ser. 6, vol. ix. pt. 1, 

 Mem. Sci. Math.-Phys. vol. vii. pp. 89-102 ; and 1882, ' Geologische Forsch- 

 ungen in den Kaukasischen Landern,' Abth. ii. Geologic des Armenischen 

 Hochlandes, i. Westbalfte, pp. 270, 273, 274, 281-283. 



