296 PROCEEDINGS OF THE GEOLOGICAI SOCIETY. [May 7, 



The characters of the neural arches can nowhere be distinctly 

 made out, though well-marked traces of them are discernible, par- 

 ticularly in the caudal region, where indications of subvertebral 

 arches, or chevron-bones, are also to be found. 



At a distance of about 19 inches from the hinder end of the ramus 

 of the mandible, and about 17 inches from the end of the tail, a 

 stout bone, 1*6 inch long, broad at each end and thinner in the 

 middle, lies obliquely across the axis of the body. Its vertebral end 

 is half an inch wide, and has a well-marked, though shallow, groove 

 or longitudinal depression on its outer surface. An oval depression, 

 filled with matrix, occupies the anterior face of the opposite end of 

 this bone. There are fragments of one or two other long bones 

 behind this ; and the ventral armour, which ends about an inch in 

 front of the bone described, is connected posteriorly, as I have stated 

 above, with two much-broken, broad, thin, bony plates. 



I take these parts to be the remains of the pelvic girdle and 

 member, though their condition is such as to render it almost im- 

 possible to decipher their precise nature. 



DESCEIPTION OF PLATE XL 



Fig. 1. Cranium of Loxomma Allmanni, one-third the natural size. 



Fig. 2. Median and lateral sternal plates of the same Labyrinthodont, 



Fig. 3. Tholidog aster ])isciformis, one-fifth the natural size. 



Fig. 4. Scales of Pholidogaster, of the natural size. 



2. On tlie FiORA of the Devonian Period in North-eastern' 

 America. By J. W. Dawson, LL.D., F.G.S., Principal of M'Gill 

 College, Montreal. 



[Pl.\tes XIL-XVIL] 

 Contents. 



I. Notices of the localities of the Devonian Plants. 



1. State of New York. I 3, Canada. 



2. Maine. I 4. New Brunswick. 



II. Descriptions of the species. 

 Angiospermous Dicotyledon. 

 Exogenous Gymnosperms. 



Coniferas. 



Sigillarias. 



Calamitese. 



AsterophyUitese. 



Acrogenous Cryptogams. 

 Lycopodiacege. 

 Filices. 

 Incertge sedis. 

 Algse. 

 III. Conclusion. 



The existence of several species of land-plants in the Devonian rocks 

 of New York and Pennsylvania was ascertained many years ago by 

 the Geological Surveys of those States, and several of those plants 

 have been described and figured in their Eeports*. In Canada 

 Sir "W. E. Logan had ascertained, as early as 1843, the presence of 

 an abundant, though apparently monotonous and simple, flora in the 



* Hall and Vanuxem, Reports on the Geology of New York ; Kogers, Report 

 on Pennsylvania. - 



