134 PALJiONTOLOGY OP OJTTAMO. 



slighly convex above, with a central non-poriferous space, round 

 whicli tlie radiating poriferous ridges occupy an exterior slightly 

 elevated zone. Cells forming a double row on each ridge, immersed, 

 with rounded mouths which are not elevated in any part of their 

 circumference above the general surface. 



In some respects Botrylloi^cra is allied to Defrancia ; but the cells 

 are not tubular, and are not free in any portion of their extent, whilst 

 the latter genus does not appear to have ever been detected in rocks 

 older than the Jurassic. I am only acquainted with a single species 

 of the genus, which is found growing upon corals in the Hamilton 

 Formation, and which I have named Botryllopora socialis. 



List of Devonian Polyzoa. 



121. Botryllopora socialis, Nich. (H.) 



122. Ceriopora ? Harailtonensis, iV?e/i,. (H.) 



123. Ptilodictya Meeki, Nich. (C. & II.) 



124. Polypora pulchella, Nich. (C. ) 



125. " Halliana, Front (C.) 



126. " tenella, Nich. (0.) 



127. " tnberculata, iV/c'A. (H.) 



128. Retepora prisca, Gol'ffuss (C. & H.) 



129. " Phillipsi, Nich. (C.) 



130. Cr3'ptopora mirabilis, Ni(h. (C.) 



131. Fenestell I ruagtiitica, iVlcA. (C.) 



132. " marginnlis, Nich. (C.) 



133. " cribrosa, Ha^l (11.) 



134. "- iemnceps, Hall {G. & \I.) 

 Uo. " filiformis, Nich. (C.) 



136. Taen'opora exigua, Nich. (H.) 



137. " peuniformis, Nich. (II.) 



138. Carinopora Ilindei, Nich. (0.) 



139. ClatlirojDora intertexta, Nich. (C.) 



V. LAMELLIBRANCFIIATA. 



Mr. Billings states that he has met with about twenty species of' 

 LamellihrancJiiata in the Corniferous Limestone of Western Ontario, 

 and of these he describes and names one, viz., Vanuxemia Tomkinsi 

 {Canadian Journal, New Series, vol. vi. p. 357). This species I 

 have not seen, and the only Lamellibranch that I have met with 

 either in the Corniferous Limestone or the Hamilton Group of 

 Ontario is the well-known Conocardium trigonale, Hall, which is not 

 of uncommon occurrence, though usually found in a veiy fi-agmentary: 

 condition. 



