54 Prof. H. A. Nicholson — New Devonian Fossils. 



show the hinge and respective position of the dental and socket plates or 

 septa. Reval, Esthonia. 



Fig. 10. — Porambonites gigas, F. Schmidt. Lower Silurian {2a of Schmidt's classifi- 

 cation). Lychholm, Esthonia. 



Fig. 11. — Porambonites {Pentamerus) ventricosa, Kulorga. Internal cast of ventral 

 valve. 11a. Interior of same valve taken in gutta-percha from the same 

 cast. Lower Silurian. From quarries near the village of Paritzy, near 

 Gatschina. This fine internal cast was found and presented to me by Prof. 

 Inostranzew. 



Fig. 12. ■ Dorsal valve from same internal cast. 12a, interior. 



Fig. 13. Interior of the rostral portion of ithe valves, to show hinge 



and respective position of dental and socket plates in each valve. Taken 



from the same internal cast. 



III.- 



-Desoriptions of New Fossils from the Devonian 

 Formation of Canada West. 



By H. Alleyne Nicholson, M.D, D.Sc, F.R.S.E.; 

 Professor of Natural History in University College, Toronto. 

 (PLATE IV.) 

 {Continued from page 16.) 

 Alyeoiites (Ccenites?) distans, Nicholson, 

 Spec char. — Corallum ramose, the branches cylindrical, of a 

 diameter of from a line and a half to two lines, dividing dichoto- 

 mously at intervals of about half an inch, but 

 not anastomosing. Corallites oblique to the 

 surface, with exceedingly thick walls. Calicos 

 extremely minute, about one-eighth of a line in 

 their longest diameter, sub-circular, transversely 

 oval, or sub-triangular, level with the surface, 

 and having the lower lip hardly or not at all pro- 

 minent. Intervals between the calices propor- 

 tionately very wide — usually about half a line. 

 At first sight this species has very much the 

 appearance of a Ccenites (such as C. intertextus) , 

 or of the uncertain form Alveolites {?) seriato- 

 poroides, Edw. and Haime. It is, however, 

 distinguished from the former by the non- 

 prominent and not markedly triangular calices, 

 and from the latter (which is almost certainly 

 not an Alveolites) by the fact that the corallites 

 are disposed obliquely to the surface. 

 Alveolites distans is readily distinguished from the other ramose 

 species of the genus by the exceedingly small size of the calices and 

 the proportionately great width between them, as well as by the 

 fact that the calices are level with the general surface or nearly so. 

 There is thus produced the fallacious appearance that the corallites 

 are imbedded in an abundant coenenchyma. 



Locality and Formation. — Corniferous Limestone, Port Colborne. 



Alveolites conperta, Nicholson. PL IV. Fig. 5, c. 

 Spec. char. — Corallum ramose, composed of cylindrical or ellip- 

 tical branching stems, which bifurcate, but do not interlace. 

 Diameter of the stems from two to three lines. Corallites minute, 



Fig. 4. — Alveolites distans, 

 Nich. a. Fragment of the 

 natural size. 6. A portion of 

 the same enlarged. From the 

 Corniferous Limestone, 



