Cretaceous Species of Podoseris, Dune. 29 



unfortunately more or less worn and weathered. Specimens 

 in a similar condition have passed through my hands since 

 1869, and there are some in tlie British Museum. Amongst 

 the collection now under consideration there are probably a 

 hundred specimens of various stages of growth and of decay, 

 whilst a few present structures which, from their ready 

 destruction under weathering, were not preserved in the speci- 

 mens formerly examined. 



The new specimens indicate that the ornamentation and 

 shape of the septa, their number, their relation to a septal 

 fossula, and the size and height of the corals vary, and that 

 the true characters of the calices cannot be appreciated by the 

 examination of weathered specimens. It is interesting to 

 notice that in the specimens which were examined and 

 described in 1869 there was a great amount of variation in 

 their height and in the convexity of the calices. No satis- 

 factory examples of the tall varieties with convex calices are 

 amongst the new series. Most of the specimens are low, 

 broad, slightly convex, with a massive-looking columella and 

 numerous large uniting septa and synapticulee. The usual 

 cyclical number of the septa is incomplete five, but there are 

 some specimens with five cycles complete, and in one very 

 broad specimen there are some septa of the sixth cycle present. 



The following is a description of what may now be con- 

 sidered to be a typical form : — 



Corallum simple, attached, with a circular base, from which 

 it rises very slightly and more or less vertically to the edge 

 of the moderately convex calice, which has a distinct central 

 fossula with the columella at its base. Broader than high, 

 12 millim. in diameter and 5*5 millim. in height. 



Septa mostly long and stout, passing far inwards, many 

 reaching, after uniting with others, the edge of the fossula 

 and uniting at its base to form, with some slight interseptal 

 structure, the columella ; all more or less arched where free 

 and carrying a single line of large distinct granules, which 

 are especially large and distinct around the fossula and upon 

 the columella ; or the position once occupied by granules may 

 be occupied by pits. The number of the septa is variable in 

 the six systems; there is either a deficiency or a redundancy 

 of large septa and the number of rudimentary small septa 

 varies greatly ; still the complete fifth cycle is rarely reached 

 in spite of there being some \Qxy remarkable long and very 

 slender and almost linear septa close to some of the largest. 

 There is union of septa either near the fossula or near to the 

 calicular margin. Septa swollen in regular series, their 

 swellings interdigitate, oblique ridges upon the sides of the 



