426 



DR. J. W. GEEGOET ON THE 



2. Oebicella. Guentheei, n. sp. 



Diagnosis. Corallum massive, and growing apparently in 

 tabular expansions. 



Corallites of medinm size ; closely packed, and therefore 

 appearing angular in shape, and usually hexagonal. Exotlieca 

 narrow but dense, forming a stout wall. 



Septa three complete orders, and an imperfect fourth order 

 represented. Seen from the exterior, the six primary septa are 

 especially conspicuous. 



Columella large, appearing substyliform. 



Diviensions. 



A-ffinities. This species is founded on three corals — one figured 

 by Abich * as Asirea Defrancei, and the other two collected by 

 Mr. Giinther in the conglomerate of Seir, 6 to 8 miles west 

 from Lake TJrmi. The corals agree very closely, the only differ- 

 ence between them is the somewhat smaller diameter of the 

 corallites in the specimens from Seir. 



The coral differs from O. Defrancei in three important cha- 

 racters : — The corallites are smaller in diameter; the wall is 

 narrower, denser, and not lamellar ; the corallites are polygonal, 

 and they are not divided by valleys or depressions between the 

 raised calycinal margins. Hence the coral appears to me quite 

 distinct from O. Defrancei. It may be distinguished from 

 O. vesiculosus (Ed. &H.)t owing to the absence of the vesicular 

 endotheca and exotheca. 



In 1882 Abich figured two additional Armenian astreans as 

 Heliastraa Defiancei. Of these the first variety J is probably 



* Abich, 1859, op. cit. p. 93, pi. ix. fig. 6 ; ? also 1882, op. cit., Heliastraa 

 Defrancei, var. 1, p. 273, pi. vii. fig. 20. 



t M.-Edwards & Haime, Mem. Astr. pt. 3, Ann. Sci. Nat., Zool. ser. 3, vol. xii. 

 1849, p. 107. 



\ Abich, 1882, op. cit. p. 273, pi. rii. fig. 20. 



