42 



Dr. J. F. Gemmill, M.A., M.D., F.Z.S., gave an account of his 

 paper on the development of some Starfishes. 



Asterias glacialis. — A small solid outgrowth from the stomach- 

 vfall is found in nearly all early larvse, and a brood occurred in 

 which this outgrowth was larger, developed a central cavity, and 

 fused with the backwardly growing coelomic cavity of the left 

 side. It is interpreted as a rudimentary posterior enterocoelic 

 outgrowth. 



Grihrella oculata. — It is shown that the perihsemal pouch 

 belonging to the madreporic interradius arises from the dorsal 

 horn of the left posterior cffilom, that the aboral skeleton arises 

 in the form of scattered plates without definite radial and inter- 

 radial arrangement, and that the terminals are formed by fusion 

 of several of these plates. 



Solaster endeca. — The author's previous description is supple- 

 mented in various points, including the following: — (1) All the 

 perihfemal pouches arise from the posterior coelom ; (2) there are 

 outgrowths from the posterior coelom to form the preoral ccelom 

 in all the interradii ; (3) closure of the hydroccele-ring takes place 

 in interra'dius viii./ix. ; (4) the mouth-angle plates and anterior 

 processes of the first ambulacrals arise as single continuous 

 calcifications. 



Stichaster roseus. — The early development of this species 

 resembles that of Asterias rubens, and, although the larva; were 

 not reared to their later stages, it is inferred as almost certain 

 that the final larval form will prove to be a brachiolaria 

 attaching itself at metamorphosis." 



The next Meeting of the Society for Scientific Business will be 

 held on Tuesday, November 21st, 1916, at 5.30 p.m., when the 

 following communications will be made : — 



Alfred Ezra, F.Z.S. 



Lantern Exhibition illustrating a Hunting Trip in Central 

 Asia. 



Prof. B. Petrontevics & Dr. A. Smith Woodward, F.R.S., Y.P.Z.S. 



On the Pectoral and Pelvic Arches of the London specimen 

 of Arehceopteryx. 



