Dr. P. M. Duncan on some Fossil Corals from Sinde. 303° 
18. Trochoseris aperta, n.sp. Pl. XIX. fig. 5. 
The corallum is simple, conical, and short ; it is circular and 
nearly flat above, except at the fossa, but slightly pedunculated 
inferiorly. The upper surface consists of a central, irregularly 
circular, and deep fossula, surrounded by a subplane and wide 
rim, which is marked by numerous and slightly exsert septal 
prolongations. The external edge of the rim is sharp and is in 
contact with the epitheca, which is marked slightly by the costal 
continuations of the septa of the rim. The fossula contains the 
projecting primary septa, a small flat columella, and the numerous 
small septa. The septa are in six systems; and in calculating 
the cycles the horizontal septa of the rim must be considered, 
although all of them do not reach the fossula. ‘The cycles are 
irregular, and there are five, with several septa of the sixth. 
The primary septa are the thickest, and project most into the 
fossula ; but they and all the others are very slightly exsert, and 
the spaces between them are either closed (as on the rim) by a 
horizontal floor which hides the numerous synapticulz, or (as 
in the fossula) by the synapticule. The primary septa, where 
projecting, are granulated laterally. The secondary septa are 
distinguishable within the fossula, but not on the rim. The 
septa of the highest orders extend only a slight distance from the 
external edge of the rim, and all are more or less dentate. The 
cost are faint elevations covered with epitheca. The synapti- 
culz are very numerous. Height of coral 1 inch. Width of 
upper surface 1,%; inch., of the fossula 5°; mch ; depth of fossula 
<4; inch. 
From the Sinde Tertiaries, Kurrachee. Coll. Brit. Mus. 
The form would resemble a large pedunculated calice of a 
Mycedium with a circular rim including the costz. I do not 
consider, however, that it is the parent calice of a compound 
species. It has only a slight affinity with Zrochoseris distorta 
of the French Eocene. 
19. Cyathoseris Valmondoisiaca, var., Edwards & Haime. 
The variety has a broader base and a greater disposition to 
run into series as regards the calices than the type. The synap- 
ticulee are numerous, and the “collines” are well developed. 
The species is found in the French Eocene at Auvert, Valmon- 
dois, Assy, and Bouconvilliers. (See Michelin, Icon. Zooph. 
p- 155 ; D’Orbigny, Prod. t. 1. p.426, 1850.) The variety, which 
resembles a Manicina, is from the Blagrove Collection of the 
Geological Society, and is found in the Hala Mountains. 
20. Cyathoseris irregularis, nu. sp. Pl. XIX. fig. 6. 
The calices are separated by cristiform walls, and are large 
