STOMA TOrORJS AND ASCODICTYA. 617 



Pig. 4. Pig. 5. Pig. 6. Pig. 7. 



4. Profile of two cells from No. 3 colony, only lower down on specimen. 



5. Magnified cell on same colony (fig. 3, a). 



6. Three cells from same colony (fig. 3, b). 



7. Cell from same colony, with caudate elongation (fig. 3, c). 



8. Cell from another colony. The stoloniferous processes on specimen No. 3 

 do not belong to the Polyzoal colony, but to Ascodictyon. Upper Silurian, 

 Buildwass beds, base of Wenlock shale, Shropshire. 



The habit of the colonial growth, as given in fig. 1, is similar 

 to that of Aulojpora dichotoma, Goldf . Generally speaking, about 

 every second cell gives origin to a fresh one ; and this is the be- 

 ginning of a new branch. I cannot, however, give this as a cha- 

 racter, on account of its variableness. The origin of fresh, colonies 

 of this beautiful species is a most interesting study. Without 

 speaking positively on this point, I have in one small fragment 

 probable evidence that clusters of cells are developed from one of the 

 "rosettes" of Ascodictyon stellatum, Nich. and Ether. * Around 

 this cluster primary cells of various colonies are disposed ; some 

 colonies have a linear arrangement of from three to five cells ; the 

 primary cells are also disposed singly on different parts of the frag- 

 ment of broken shell ; a larger mass of cells clustered in one spot 

 give origin to several linear branches of what I am disposed to 

 believe are new colonies. It may, however, be possible to explain 

 this feature by stating that one rosette gives origin to several linear 

 branches, and the whole clustered together would be the parental 

 nucleus of one colony variously disposed. There is sufficient evi- 

 dence to show that some colonies at least sprang from an inde- 

 pendent primary cell. 



Amongst living JStomatoporce a most remarkable feature is shown 

 in the figures of S. fasciculata, Hincks, pi. lix. figs. 4, 5 f . In his 

 descriptive text (p. 441) Mr. Hincks separates this from all other 



* Ann. & Mag. Nat. Hist. June 1877. 



t Hincks, Brit. Marine Polyzoa, vol. ii. ; text, vol. i. 



