134 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



stome. Buccal pores near peristome. Prominent bulge occurring 

 longitudinally in median area of each phyllode (pi. 20, fig. i). 



Tiiberculation. — Tubercles on adoral surface much larger than 

 those on adapical ; no tubercles in median area of interambulacrum 5 

 adorally. 



Occurrence. — Upper Cretaceous (Senonian), Arrialoor group, in 

 southern India. 



Location of type specimen. — Unknown. 



Remarks. — Forbes (1846), d'Orbigny (1856, p. 333), and Sto- 

 liczka (1873) apparently were unaware of M'Clelland's description 

 of Gongrochanus herschclianus when they described or referred to 

 Gongrochanus elatus, a species which is certainly conspecific with it. 

 According to Stoliczka, the species is very variable, with smaller 

 specimens being more elongate and lower than larger specimens. It 

 was this variability that caused M'Clelland to erect seven species for 

 specimens which probably belong to the same species ( see Das-Gupta, 

 1921, p. 297). 



Mortensen (1948, text fig. 195) shows a posterior view of Gongro- 

 chanus herschelianus which he cites as being copied from d'Orbigny 

 (1856, pi. 929). d'Orbigny in his text says that the species is figured 

 on his plate 929, but this is an error, for Pygorhynclms obovatus is 

 figured there. Mortensen's figure must have been copied from Forbes 

 (1846, pi. 19, fig. lb, published in 1856). 



Genus PYGUROSTOMA Cotteau and Gauthier 



Pygurostoma Cotteau and Gauthier, 1895. Mission scientifique en Perse par 

 J. de Morgan, vol. 3, pt. 2, Paleontologie, p. 51. Type species by monotypy, 

 Pygurostoma morgani Cotteau and Gauthier. 



GENERIC DESCRIPTION 



Medium to large, elongate, low ; apical system anterior, tetrabasal ; 

 periproct marginal to inframarginal, longitudinal ; peristome trans- 

 verse pentagonal ; petals broad, equal, closed, conjugate pores ; am- 

 bulacral plates beyond petals single pored ; bourrelets well developed ; 

 phyllodes broad, single pored, with many pores, buccal pores small, 

 widely separated from edge of peristome. 



Comparison with other genera. — Pygurostoma is quite distinct 

 from the other genera in the family Faujasidae. Its floscelle, how- 

 ever, is very similar to that found in Gongrochanus, having many 

 single pores and strongly developed bourrelets, but Pygurostoma 



