162 PEOF. p. MABTIN DUNCAN's EEYISION OP THE 



This genus, characterized by ibs solid septa, walls, and synap- 

 ticula, and serial calices, includes Mceandroseris, now Plesioseris, 

 australice, Eousseau, sp. 



Grenus Pachtseeis, Milne- Edwards Sf Jules Saime, Sist. Nat. 

 des Corall. vol. iii. p. 85 (1860) ; Duncan, Jouroi. Linn. Soc, 

 Zool. vol. xvii. p. 309 (1883), and Pal. Indica, Series siv. Foss. 

 Corals Sfc. of Sind ; amended. 

 Colony adherent, foliaceous, very variable in shape. Base a 

 thin solid wall, wliich is costulate. Upper surface presenting long 

 concentric eminences or collines and intermediate valleys, the 

 first crossed by parallel septo-costae, the latter showing an axial 

 space, with or without a projecting columella close to the end of 

 the septa. No distinct calices or radiating series of septa. The 

 series of septa in the valleys are long and very bifurcate. Colu- 

 mellary space very long and filled up by series of tabulate dis- 

 sepiments. Septa close, finely dentate and graiiular on their 

 sides, rarely perforate. Synapticula long vertically, and occu- 

 pying the position of a colline-wall, and small and nodular, and 

 placed on the septa close to the columellary space. 



Distribution. — Fossil. Lower Eocene of Sind, Miocene of Sind. 

 — Becent. Pacific and Indian Oceans. 



Grenus Comoseeis, d' Orhigny, Note sur les Polyp, foss. p. 12 

 (1849). 



Colony thick, attached or free, base covered with a stout epi- 

 theca. Upper surface with calices more or less close, distinct 

 at their centres, and with confluent septa, separated at certain 

 points by collines, over which the septo-costae pass. Collines 

 long or short, narrow or broad, straight or curved, radiating 

 from the centre of the upper surface or not. A rudimentary 

 columella. Septa united by synapticula. No wall around the 

 calices or in the collines. A basal wall, which is solid and 

 marked with costse, underlies the dense epitheca. 



Distribution. — Fossil. Jurassic : Europe. Cretaceous : India, 



There is a very fine specimen of Comoseris irradians, Ed. & H., 

 in the Museum of the Gi-eological Survey in Jermyn Street, which 

 shows the construction of the septa and synapticula very well. 

 The septa are slender, trabeculate, but imperforate, and there 

 are the same kind of endothecal processes as are seen in Tham^ 

 nastrcea. 



The epitheca is worn ofi", and the striated, costulate, basal wall 



