284 



Cf. Schmidt, Spong. Adriat. Meeres (1862) p. 46—47; PI, IV, 

 figs. 2 und 4. 



Schmidt, Suppl. Spoug. Adriat. Meeres (1864) p. 31—32; 

 PI. III, figs. 6 und 7. 



Schmidt, Spong. Kust, Algier (1868) p. 31. 

 Sollas, Chall. Tetractin. (1888) p. 181—182. 

 Marenzeller in : Ann. K. K. naturhist. Hofmus. Wieu. Bd. 



IV, (1889) p. 10—11; PI. II, fig. 1. 

 Auchenthaler ibid. p. 1 — 6; PI. I. 



V. Lendenfeld und Schulze in : Anh. Abh. Akad. Wiss. 

 Berlin. (1890). 



The shape of S. grubii O. S. is as a rule irregularly spherical ; 

 Auchenthaler described a flat specioaen. The surface is generally 

 covered by foreign bodies or other sponges; if cleaned from these 

 often the honeycomb-like appearance as Schmidt stated for his 

 S. dorsigera, is conspicuous. They can reach the size of a child's 

 head. The colour is dark violet-grey, brownish black or greyish. 



A section through the living animal exhibits a pale yellowish 

 parenchyme and a dark cortex. Cortex and parenchyme are often 

 sharply separated from each other by a white line of demarcation. 

 The parenchyme is rather compact and shows some large holes: 

 the sections of main exhalant canals. The water enters through 

 stomions into canals which are sometimes rather long and debouch 

 together into a chone. The chones are by no means always dis- 

 tinctly marked out; but a comparison between many sections of 

 this sponge and of others seem to prove that we have in fact 

 to do with chones. 



Under the fibrous cortex there is a system of crypts. Under 

 the dermis there is a system of subdermal cavities, which are 

 however not always easily recognised , e. g. under the stomions. 

 Still, I think it quite certain that a portion of the first inhalant 

 canals is due to these cavities. Large lacunae are in communica- 

 tion with the crypts. It is only from these lacunae that the rami- 

 fying inhalant canals start. The prosodi are a little longer and 



