Marsiiinum in Echinoid. 141 



The only group of Echinoids in which a definite marsupium 

 has been recorded, as far as I am aware, is that of the Spatan- 

 goids. In them those forms with i-unken petals, such as Hemi- 

 aster and Schizaster, the pits in some cases, and perhaps in all, 

 function as brood pouches. In Hemiaster cavernosus, the pits 

 are present in the female, absent in the male, so that they 

 furnish an external sexual character. 



Eleven of my specimens have a marsupium, while the re- 

 mainder are without it. Its presence, then, if we may argue on 

 the analogy of Hemia-ster, indicates the female. 



In some of the Cidaroids a temporary protection is afforded 

 to the young by the tent-like arrangement of the spines, but 

 there is no pitting in the te«t, as in the case of Spatangoids, 

 or as in the present specimens. It is consequently of interest 

 to find the permanent n^arsupium present in a second order of 

 Echinuids, the Clypea^teroida. 



The question as to the name of the species is not easy to settle. 

 The amount of specific vairiation amongst echinoids is considei'- 

 able, and there is a growing tendency to limit the number of 

 specific forms. F. Jeffrey Bell is one of the most eminent of 

 those who hold this view.-l 



We have already two species of Scutellina described from our 

 Australian older tertiary — namely, S. patella, Tate^ and S. mor- 

 gani, Cotteau.^ Although there are certain details of Cotteau's 

 species that I cannot decipher in specimens from Mount Gam- 

 bler, the locality of the tjrpe, yet I have no doubt that Tate's 

 and Cotteau's species are identical. Tate in his description gives 

 Mount Gambler as one of the localities from which his species 

 was obtained. The species is widely spread, being found in 

 almost all our tertiary limestones. 



The question of priority is not easy to settle, for both paper's 

 are dated 1891. Professor Tate, many years ago, when acting 

 as editor of the publications of the South Australian Society, 

 told me that the publications for the year always appeared in 

 that year, so that though his present paper was read only in 

 October, it almost certainly appeared in 1891. Cotteau's paper 



1 Marine Investigations in South Africa, vol. iii. 



2 Trans. Roy. Soc. S. Australia, 1891, p. 279. 



3 Mem. Soc. Zool. d'i France, pt. iv. (1891), pp. 629, 630, pi. 19, figs. 10-14. 



