ALCYONAEIA OF SIND. 91 



Genus PLESIASTE^A, M. Ed. & J. H. 



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1. Plesiaste^a costata, Bwncan. Plate XXIV, Figs. 9, 10. 



The corallum is massive, nearly fiat above, and short. Numerous corallites project, 

 some obliquely from the common surface over which the costse pass, and most are 

 in cones, vpidely truncated and crateriform, whilst a few are oval or elliptical in their 

 calicular outline. The calices, usually circular in outline, are not deep, and the well- 

 marked costse merge into thick and exsert septa at the margin. The septa, not crowded, 

 are alternately large and very small, are thick at the wall, and the larger become 

 thinner as they plunge with an arched edge into the fossa, to end in blunt 

 nodular-shaped, compressed pali : there are four cycles in the largest calices, and the 

 pali are before all except the last, whose septa barely project within the wall. The 

 columella is large and strongly papillary. The costse are thicker than the septa, cover 

 the outside of the wall, are stout, wide apart, and have rounded projections on them ; 

 The smaller are in contact with the smaller septa. 



Diameter of calice \ inch. 



Height above common surface -^q inch. 



Locality. Naigh Nai, south-west of Sehwan, Gaj series. Survey-number G ■\^. 



Illustrations of the Species in Plate XXIV. . 



Fig. 9. A portion of the coral : natural size. 

 10. A calice : magnified. 



2. Plesiaste^a decipiens, Duncan. Plate XXI, Figs. 3, 4. 



The corallum is very large, massive, and slightly gibbous on its upper surface. The 

 corallites are more or less raised above the common surface and have well-marked costse. 

 The corallites are united by much exotheca, and the bluntly but distinctly spined costse 

 pass over it. The calices, usually circular, vary greatly in size ; the larger project, and 

 have a very shallow fossa and the costse well marked around the margin, whilst the 

 smaller, equally complete, often barely project. 



The columeUary space is circular and distinct, and the columella has small papillse 

 on it. The septa vary much in number ; but the larger are subequal, and a minute one 

 is between them. According to the size of the calice, there may be 9, 10, 12, to 16 

 large septa, and as many rudimentary ones. The costse are well developed, stand out, 

 and are bluntly spiny, especially near the intercalicular surface. Small but very distinct 

 elongations of the large septa exist, resembling pali. 



The budding is extracalicular and on the common exothecal surface. The pali 

 are small and before the long septa. 



Height of specimen 2 inches. 



Diameter of the calices : largest, \ inch ; smaller, xo inch. 



Locality. Sita Nai, Gaj series. , Survey-number G ^-. 



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