316 Scientific Proceedings, Royal Dublin Society. 



the tentacle, and it is their presence, of course, which gives rise to 

 the fluted appearance in the living animal (PL iv. fig. 1). 



Professor Hertwig found similar flutings in the tentacles of 

 Dysactis crassicomis, R. Hertwig, and transverse sections of the 

 tentacles of this Actinia exhibited a somewhat similar structure to 

 what has been described in Bunodes thallia ; in Dysactis crassicomis, 

 however, the muscle lies in the mesogloea. (Hertwig, " Challenger " 

 Report. Supplement, p. 17.) Grosse mentions flutings as being on 

 the tentacles of the genus Bolocera (Actin. Brit., pp. 186 and 351), 

 and we have found similar markings in Tealia crassicomis ; but of 

 this hereafter. There would appear to be no doubt that there is 

 one tentacle rising from each endocoele and exoccele respectively. 

 In two of the specimens in which we were able to count the 

 tentacles during life, we found, on cutting transverse sections of 

 the body, that the number of mesenteries was precisely the same as 

 that of the tentacles, there being forty-six tentacles and twenty- 

 three pairs of mesenteries in the one, and thirty-two tentacles and 

 sixteen pairs of mesenteries in the other. 



Warts. — A transverse section shows that the warts are 

 developed only in the endocceles and in the spaces between the 

 directive mesenteries. They appear much more conspicuously in a 

 longitudinal section of the body wall cut down through one of the 

 endocceles : here they are seen as evaginations of the body wall, the 

 endodermal muscular layer being not so thickly pleated throughout 

 the region of evagination as in the other parts of the wall (PL iv. 

 fig. 4). There is a considerable accumulation of black pigment 

 granules all through the endoderm, but especially in the evaginated 

 portion in each wart. Precisely similar structures (endodermal 

 saccules) have been observed and figured by Hertwig in Tealia 

 bunodiformis, (R. Hertwig, "Challenger" Report, p. 36, pi. 8, 

 fig. 4), and by Jourdan in Bunodes verrucosa (An. des Sci. Nat. 

 Zool. ser. 6, vol. x. (1879-1880), p. 78, pi. 7, fig. 48). Hertwig, 

 however, did not identify these evaginations with the warts which 

 he states to have been present in Tealia bunodiformis, and Jourdan 

 considers the warts (vermes glandulaires) to originate from the 

 ectoderm alone. Jourdan's theory has been criticised and rejected 

 by Professor Hertwig ("Challenger" Report, pp. 84, 85), in 

 describing Bunodes minuta, R. Hertwig. The learned Grerman 

 author found that the constitution of the wall of that Actinia 



