BRYOZOA—CTENOSTOMATA. 



17 





FlG. 177. a, Khopalonaria venosay^g; b, Ascodiclyon florealey^g\ c, Vinella 

 repens y^l\ d, Allonema fusiformey^g; e, Vinella repensy^\%. (After Ulrich, 

 and Ulrich and Bassler. ) 



3. R. tenuis U. and B. # Devonic. 

 Like R. venosus, but fusiform cells narrower and longer, and 



connecting stolons shorter. 



Hamilton beds of Western New York, Canada and Michigan. 



II. Ascodictyon Nicholson and Etheridge. 

 Attached to shells, etc., and consisting of ovate or pear-shaped 

 vesicles in clusters or single, arranged along delicate hollow threads 

 or stolons. Zocecia unknown. Sil.-Miss. 



4. A. stellatum N. and E. Mid-Devonic. 

 Ovoid or pear-shaped calcareous vesicles, generally in clusters 



of six or more (sometimes fewer) cells, averaging nearly I mm. in 

 diameter, and connected by filamentous tubes. 



Hamilton beds of Western New York and Ontario. 



5. A. floreale U. and B. (Fig. 177, b.) Mid-Devonic. 

 About half the size, of the preceding. 



Hamilton of Michigan. 



