Dr. Alex. Broion — On Solenopora. 195 



habits and mode of life of these two herbivorous Dinosaurs were 

 doubtless very similar. 



The type specimen of Gamptosaunis dispar, used as the basis of 

 the present restoration, is from the Atlantosaurus beds of the Upper 

 Jurassic of Wyoming. This species and other allied forms will 

 be fully described in an illustrated Memoir now in preparation by 

 the writer for the United States Geological Survey. The present 

 restoration is reduced from a large drawing made for that volume. 



11- — On the Structure and Affinities of the Genus Solenopora, 



TOGETHER WITH DESCRIPTIONS OF NeW SpeCIES. 



By Alex. Brotvn, M.B., M.A., B.Sc. ; 

 Assistant in the Natural History Department in the University of Aberdeen. 



(Part II.) 



[Continued from the April Number, p. 151.) 



5. Solenopora filiformis, Nich. 



Solenopora filiformis, Nicholson, Geol. Mag. 188S, Dec. III. Vol. V. No. 1, p. 21. 



" It presents itself sometimes in the form of small rounded 

 masses, or irregular nodules ; or at other times as lobate or 

 ramified masses of considerable dimensions. Viewed with a 

 powerful magnifying-glass, it appears to be quite compact or 

 obscurely fibrous" (Nicholson). 



The internal structure is commonly much obscured, or even 

 destroyed by crystallization. In vertical section the cells are 

 arranged in radiating fashion. Cells narrower and shorter than 

 in Solenopora compacta, diameter being -^^ mm. Cell-walls thin 

 and not wavy (Fig. 6a). In tangential section the cells have 



B 



i\g 



Fig. 6. — A, Long. sect, of Solenopora filiformis , Nich., from the Ordovician Lime- 

 stones of Craighead, Girvan, Ayrshire, x 60 d. B, Tang. sect, of the same. 



polygonal walls. They appear to increase by ordinary cell-division, 

 but the active condition has not been observed (Fig. 6 b). 



Observations. — This species seems to be an intermediate form 

 between S. compacta and S. Jurassica. The cells are not so 

 elongated as in S. compacta, and are more like what one finds in 

 S. Jurassica ; only in the latter the transverse cell- walls are concave 



