OF WESTERN SIND. 271 



V. APPENDIX. 



This Fasciculus contains the description of the uppermost Nummulite-bearing rocks of 

 Sind, and the next, which will be published shortly, will relate to the Miocene strata 

 of the same province. As that Fasciculus will be the last of this Series, it will contain 

 the necessary lists of the species of the Echinoidea, and also the remarks upon the affi- 

 nities of the faunas of the consecutive great groups of strata. The affinities of the 

 Nummulitic, Oligocene, and Miocene faunas of Sind will then be considered in relation 

 to those of the equivalent European strata. 



In concluding this part of our work it becomes necessary for us to introduce here 

 some remarks which we have already published in the 'Annals and Magazine of Natural 

 History' for October 1884. 



A species of the genus Hemiaster {H. elongatus) was described by us in page 78 

 of the fasciculus on the Echinoidea of the Ranikot series, and it was figured on 

 Plate XIX. 



Professor Sven Loven, in a masterly essay on the genus Pourtalesia, communi- 

 cated to the Royal Swedish Academy of Sciences, June 1882, and which was published 

 in 1883, stated in two footnotes, one on page 73 and another on page 79, that our 

 species H. elongatus belongs to the genus Palceostoma. It is evident to us that if this 

 is true, another species {Hemiaster digonus, d'Archiac) must come within the same 

 generic environment. We have gone over the descriptions and drawings of both these 

 species, and have compared them with the original types, and we still retain the forms 

 in the genus within which they were placed by us. 



The following extract from the ' Annals and Magazine of Natural History ' for 

 October 1884, p. 239, places our views definitely : — 



" We may admit that the two species of Hemiaster differ equally from Pate- 

 ostoma. 



" In all the forms the apical system is small, and two of the generative plates, 

 1 and 4, have conical eminences, on which are the large ovarial pores. 



" In all three forms the generative or basal plates 2 and 3 are small and without 

 perforations for ovarial ducts, and here the structural similarity ceases. The genus 

 Palceostoma has no madreporite passing back between the two perforated plates 1 and 4 ; 



2o 



