Spongia coriacea of Montagu. 23 



deated graniiliferous cells or bodies like the "investing mem- 

 brane" of Spongilla, -wVxch. in combination there appeared 

 to me to have the power of opening and closing a pore 

 wherever they liked (see " Ultimate Structure of Sjjongilla,''^ 

 ' Annals,' 1857, vol. xx. pp. 24, 25, pi. i. figs. 6, 7) ; the 

 " Wanderzellen " or migrating, amoeboid cells of Schulze 

 (Zeit. f. w. Zool. 1878, Bd. xxx. S. 409 &c.) ;— and the latter 

 or excretory division, consisting of the general tubulation 

 of tlie reticulated thread, opening in the way and at the vents 

 mentioned ; homologous with the cloaca in the other forms 

 of the CalcispongiiB, as before mentioned. 



The process of reproduction by ova &c. is probably tlie 

 same as that of the other Calcispongige ; but in the hope of 

 determining this as well as when the elements of reproduction 

 begin to appear, I have gathered living specimens of Glathrina 

 coriacea, Grantia coinpressa, and Grantia ciliata, var. spini- 

 sjnculum (being together), from the " Rocks " here every lull 

 moon {i. e. the " springs "), since the 11th of March last in- 

 clusive, at which time I could see no trace of these elements 

 in either of these species. They began to appear in the two 

 latter on the 10th of April, and were strikingly developed, 

 especially in Grantia compressa, on the 12th of May, but not 

 advanced then beyond the ««;?segmented stage. In Glathrina 

 coriacea no trace had then a]:)peared ; nor is there any now on 

 h e 9th of June, altliough the fragments (taken from diffe- 

 rent localities) were placed in pure spirit directly they were 

 taken off the "Hocks," which preserv^es the collar and the 

 cilium of the spongozoa in their extended state. It is there- 

 fore plain that Glathrina coriacea, in point of time, does not 

 develop its ova and spermatic cells so soon as Grantia com- 

 pressa and Grantia ciliata, var. spinispiculum. My observa- 

 tions on the former in this respect for the other summer 

 months will be communicated hereafter. 



As before stated, the general structure of Glathrina coriacea 

 = Grantia clathrus &c., that is, the reticulation formed by 

 the continuous anastomosing of a hollow thread-like fibre or 

 tube, is common to many Calcispongise, which Hackel has 

 divided according to their spiculations respectively, so that 

 they appear in several genera of the first two families of his 

 "natural system," viz. the "Ascones" and "Leucones;" 

 but of themselves they equally form a natural group in general 

 structure as distinct as it is totally different from that of the 

 other Calcispongiffi, that is, the anastomosing reticulation. 

 Moreover, the little Australian calcisponge which I have de- 

 scribed and illustrated under the name of Leucetta clathrata 

 ('Annals,' 1883, vol. xi. pi. i. figs. 13-17) must form the 



