The Cretaceous Fauna of PondolamJ. 281 



interambulacra, relatively large, with four perforated genitals. 

 Madreporic plate well developed, separating the posterior genitals. 



Anterior ambulacrum in a broad, deep furrow, which is continued 

 to the peristome and causes a rather deep undulation at anterior 

 margin of the test. The petaloid part extends to between a half and 

 two-thirds of the distance from the apical disc to the anterior 

 margin ; poriferous zones widely separated, with from 15 to 18 

 rounded pores in each row. The pores in each pair are of nearly 

 equal size, slightly oblique, and rather close together. Beyond 

 the petaloid part a few single pores may occur. 



Antero-lateral ambulacra with the petaloid parts in broad, deep 

 furrows, extending to about four-fifths of the distance from the 

 apical disc to the margin. Pores elongate, about 27 in each row; 

 those of each pair widely separated, with granules between them. 

 Poriferous zones at first diverge rapidly, and at the extremities 

 converge slightly. Interzonary space rather narrower than the 

 poriferous zones. 



Posterolateral ambulacra similar to the antero-lateral, but with the 

 petaloid parts of about two- thirds of the length of those of the latter, 

 and with about 18 pairs of pores in each row. Between the rows of 

 pores in each zone are granules. 



Interambulacra much elevated between the petaloid parts of the 

 ambulacra, especially the anterior interambulacra which are narrower 

 than the petaloid parts. The interambulacral areas are ornamented 

 with many small tubercles, which become larger on the base of the 

 test, especially on its anterior portion ; on the plastron they are 

 closer together. 



Peristome transverse, with projecting labrum, at about a third of 

 the total length from the anterior margin. Periproct oval, near the 

 summit of the truncated posterior end. Fasciole well developed, 

 broadest where it crosses the anterior ambulacrum, and bending in 

 rapidly immediately behind the antero-lateral ambulacra. 



Affinities. — Stoliczka describes eleven species of Hemiaster from 

 the Cretaceous deposits of Southern India, two of which, II. front- 

 acutits '■^^ and H. indicus,]- present some resemblance in form to 

 H. Forbesi, but differ from it in other respects. 



* Cret. Fauna S. India, vol. iv. (1873), p. 13, pi. i., figs. 7, 8. 

 t Ibid., p. 16, pi. ii., figs. G, 7 ; pi. iii., fig. 1. 



