Dr. J. E. Gray on Testudo chilensis. 15 



ing large, transparent, subcircular, nuclear (?) body (a), small 

 nucleolar (?) body (b), minute globular cellules charged with 

 one or more colourless granules (c), sarcodal subfibrous trania 

 in which the cells are imbedded {(1), cavity of the same in which 

 the cell is situated (e), separate cellule much more magnified 



N.B. This figure is taken from cells in a portion of the sponge 

 which had been placed in spirit and water, where the cellules 

 were much broken down and the nucleolar body appeared not 

 only to be nucleated itself, but to be in contact with the nuclear 

 body. 



Fig. 15. Stelletta lactea, n. sp. : fragment of sandstone rock, showing three 

 portions of the sponge in the excavations made by Saxicavce 

 respectively (a a a), natural size ; dermal surface bearing minute 

 grains of sand [b), body-substance (c), black pigment lining the 

 cavities occupied by the sponge (d). 



Fig. 16. The same, diagram section, much magnified, showing rounded 

 grains of sand adhering to the dermal layer («), dermal layer 

 densely charged with minute stellates {h), zone of trifid and 

 trifurcate spicules which have their heads in contact with the 

 dermal layer (e), body -substance {d) charged with acerate, trifid, 

 and stellate spicules, together with the sheaf-shaped bundles of 

 minute acerate ones. 



Fig. 17. The same, acerate fusiform spicule, straight in this point of view, 

 but slightly curved when viewed laterally : a, real length. 



Fig. 18. The same, trifid spicule, lateral view : a, real length. 



Fig. 19. The same, trifid form with furcate extremities. 



Fig. 20. The same, portion of body-substance gTeatly magnified, showing 

 the stellates (a), the sheaf-like bundles of minute acerate spi- 

 cules (h), and the large acerate fusiform spicules. 



Fig. 21. The same, stellates of the dermal layer, much magnified : a, with 

 large body and short rays ; i, with small body and long rays. 



Fig. 22. The same, sheaf-like bundle of minute acerate spicules of the 

 body-substance, magnified, on the same scale. 



II. — Reply to Dr. Sclater's Paper in the 'Annals^ on Testudo 

 cliilensis (&c. By Dr. J. E. Gray, F.R.S. &c. 



In reply to Dr. Sclatcr on Testudo chilensis &c., in the 'Annals' 

 for December 1870, p. 470, I have only to observe that for the 

 accuracy of the habitat of the animals which I described as 

 coming from the Zoological Society, I am solely dependent on 

 the information which I obtained from that institution ; and 

 in the case of the tortoise, I took particular trouble, as the 

 discovery of another tortoise in America was a matter of in- 

 terest. This being the case, whatever inaccuracy there may 

 be in the habitat is no fault of mine, but that of Dr. Sclatcr 

 and his subordinates. 



It is much to be regretted that an accurate record is not 

 kept of every animal as it is received by the Society, stating 

 how it was obtained, and giving the details of its habitat, 



