MADEEPOEAEIAK SUBFAMILY LOPHOSEEHSTiE. 309 



wall ruDning along the long axis of the collines, whatever may be 

 their length ; and the calices, even when in close series, are limited 

 by a mural growth. The septa are not trabecular ; and it is only 

 near the columella, which is partly formed by ascending processes 

 of their curved edges, that there is any sign of porosity. The 

 septa join to form those of the principal orders in some parts of 

 calices ; and the synapticula are of two kinds — -large, tall, and ver- 

 tical near the wall ; and small, short, and irregularly placed nearer 

 the inner edge of the septa. The specific diagnosis* does not 

 consider the internal structure in anyway. " Thecorallum is in 

 a convex mass, globose, and even irregiilarly nodular, and crested 

 on the surface. The series of calices are short and slightly con- 

 fused ; and they are separated by low collines. The calicular 

 centres are distinct. The columellary is papillary and tolerably 

 well developed. The septa are thin, close, very crisped, and 

 there are about 20 to a calice ; they are of different sizes, and 

 the small often unite with the larger. The breadth of a calice is 

 3 millim." The crisped warty spinulose granules of the free 

 surface are very marked features. The granules on the flanks of 

 the septa are well marked, and never coalesce. 



The form comes under the genus Plesioseris, gen. nov., amongst 

 the Lopho serin 88. 



Corallum m^ive, compound, adherent, without epitheca. 

 Surface irregular and nodular. Calices in short series confluent 

 by their septo-costse ; centres distinct. Columella- wall developed 

 and papillary. Septa uniting ; laminae solid except near the 

 axial space, where ascending oblique processes are trabeculate. 

 Granulation warty and spinulose on the free edge, distinct and 

 separate on the laminae. Series of calices separated by short col- 

 lines ; valleys moderately deep and narrow. Walls in collines 

 and around calices. Synapticula of two kinds — one, long, broad, 

 vertical, in two rows near the wall ; another, small, nodular, near 

 th.e axial space. Grrowth by gemmation beyond and between the 

 calices. 



The solid nature of the septa and the mural structures sepa- 

 rate the genus from Maandroseris. 



TV. The Structure of the Genus Pachyseris. 

 Probably there is no genus of Zoantharia Sclerodermata 

 which so little maintains the ordinary idea of a stony coral as 

 * ' Hist. Nat, des Corall.' vol. iii. p. 62. 



