328 Ur. T. D. A. Cockerell's Notes on Slugs, 



Fig. 9. Tangential section of Stromatopora antiqua, Nich. & Murie, from 



the Niagara Limestone of Thorold. Ontario. 

 Fiff. 10. Vertical section of the same, similarly enlarged. 

 Fiff. 11. Part of a tangential section of the same, enlarged about twenty 



times. 



Plate IX. 



Fiffi 1. Tangential section of Aetinostroma matutinum, Nich. Chaleur 



Formation, L'Anse au Gascon, Quebec, The section cuts the 



laminae obliquely. 

 Fiff. 2. Vertical section of the same. 

 Fiff. 3. Tangential section of Aetinostroma Whiteavesii, Nich. DeTonian 



Rocks, Little Red River, Canada. 

 Fig. 4. Vertical section of the same. The section is not strictly vertical, 



and the radial pillars appear therefore to be more broken and 



interrupted than they really are. 

 Fig. 5. Tiingential section oi Sti-omatopora Carferi, Nich., from a boulder 



of Silurian Limestone, Hayes River, Hudson's Bay. 

 Fig. 6. Vertical section of the same. 

 Fig. 7. Tangential section of Stromatopora borealis, Nich. Silurian 



(Upper Oesel Formation), Kattripank, Oesel. 

 Fig. 8. Vertical section of the same. 



Plate X. 



Fig. 1. Tangential section of Actinostro^na exjjanswm, Hall and Whitfield, 



sp. Devonian Formation, Rockford, Iowa. 

 Fig. 2. Vertical section of the same. 

 Fig. 3. Tangential section of Aetinostroma fenestratum, Nich. Devonian 



Rocks, "Pentamerus Point," Lake Manitoba. 

 Fig. 4. Vertical section of the same. 

 Fig. 5, Tangential section of Syringostroma nodidatum, Nich. Cornife- 



rous Limestone, Kelley's Island, Ohio. 

 Fig. 6. Vertical section of the same. 

 Fig. 7. Portion of the surface of an exfoliated lamina of the same, 



natural size. 

 Fig. 8. Tangential section of Syringostroma densum, Nich. Corniferous 



Limestone, Kelley's Island, Ohio. 

 Fig. 9. Vertical section of the same. 



XXXIV. — Notes on Slugs, cMejiy in the Collection at the 

 British Museum. By T. D. A. Cockeeell. 



[Continued from p. 107.] 



VI. The Pirainea Section of Amalia. 



That section of Amalia which includes A. gagates, called by 

 Lessona and Pollonera Pirainea, differs very much from 

 Tandonia in its distribution. The latter is strictly confined 

 to the European region, the occurrence of a species in 



