298 Journal of the Asiatic Society of Bengal. [NS., XVI, 
the oral surface, while the specimens of M’clelland’ have 
oral surface as casts. Ina short note dealing with the upper 
eretaceous rocks of Assam! Dr. Spengler mentioned the 
occurrence of Stigmatopygus elatus, Forbes in them, and there is 
no doubt that under this name Dr. Spengler refers to the 
forms determined as Cyrtoma Herschelliana, J. M., 
tigmatopygus elatus, Forbes was originally described as 
Nucleolites (Cassidulus) elatus.» The genus Stigmatopygus 
was established by d’Orbigny in 1885° with S. galeatus as the | 
e species and N. elatus was transferred to this genus, an 
It 
referred to the same genus.’ As far as can be judged 
by the materials available to me it appears that the Khasi hill 
of the Khasi hill specimens shows the five buccal tubercles 
and rosettes. 3 
In his work dealing with the revision of the echinoid genus 
the late Prof. Duncan put Cyrtoma as synonym of Pygor- 
hynchus, Agassiz,> but my study of the nature of Cyrtoma 
has led me to hold an opinion quite different from this and 
that for reasons given below. 
Pygorhynchus was originally described as a distinct genus 
by Agassiz, but a sub-generic value was assigned to it by 
Duncan who put it under the genus Cassidulus, Lam.’ 
_ | Centralbl. f. Min, Geol. u. Pal. 1915, pp. 621-623. This paper, 
being published during the war, was not previously available in Caleutta, 
nly very recently a reprint of the paper arrived bere and Prot. Vre- 
mtn very kindly drew my attention to it for which I am thankful 
im. 
2 Trans. Geol. Soc., Vol. VII, p. 162. 
3 Pal. Fr. terr cret., Vol. VI, p. 331. 
al. Ind. Ser., VIII, Vol. IV, p. 98 (1873). 
5 Pomel: Echinodermes. p. 65. 
6 Pal, Fr. terr-cret., Vol. VI, p. 331. 1 M’clelland op. cit., p- 185 
1. Linn. Soc. (Zoo! 891). 
9 Op. cit., p. 182. Forbes considered Pygorhynchus to be a sub- 
genus of Nucleolites (Trans. Geol. Soc. Lond. 2nd Ser., Vol. VII, p. 161). 
Stoliczka pointed out that there was very little difference between 
Cassidulus and Pygorhynchus (Pal, Ind. Ser. VIII, Vol. 1V, p. 99, 1873). 
