AIR-BREATHERS OF THE COAL PERIOD. 275 



EXPLANATION OP PLATE VI, PIGS. 32 TO 46. 



Hylerpeton Dawsoni. 



Fig. 32 — Portion of maxillary bone with teeth. 



" 33 — Lower jaw and portions of skull. 



" 34 and 35 — Teeth magnified. 



" 36 — Cast of pulp cavity of a tooth. 



" 37 — Cross section of tooth magnified. 



" 38 and 39— Bodies of Vertebra. 



« 40 — Fragments of ribs. 



" 41 — Bony scale natural size and magnified. 



" 42 and 43 — Surface of bone magnified. 



« 44_Foot. 



■" 45 — Bone of same magnified. 



41 46 — Section of bone highly magnified. 



XI. — Additional Reptilian Remains. 

 Plate VI, Figs. 47, 48, and 54 to 56. 



Beside the species above described, Mr. O. C. Marsh, in 1861,* 

 added a new animal to the Joggins reptilian fauna ; the Eosau- 

 m$ Acadianus. The species is founded on two large biconcave 

 vertebrae, in many respects resembling those of Ichthyosaurus, 

 and indicating a reptile of greater size than any hitherto dis- 

 covered in the coal, probably of aquatic habits, and possibly allied 

 to the great Enaliosaurs or sea lizards of the mesozoic rocks. 

 The specimen was found in a bed of shale belonging to group 

 XXVI of my Joggins section, in the upper part of the middle 

 coal measures, and about 800 feet above the bed which has 

 afforded the remains described in previous sections. The beds 

 belong to one of those intervals of shallow water deposition of 

 sediment, which separate the groups of coal beds ; and on one of 

 them I found some years ago the footprints of Dendrerpeton. 



The vertebrae of Eosaurus have been fully and ably described 

 by Mr. Marsh in Silliman's Journal. Agassiz and Wyman regard 

 their affinities as enaliosaurian. Huxley suggests the possibility, 

 founded on his recent discovery of Anthracosaurus Russelli, that 

 there may have beeu Labyrinthodont batrachians in the coal pe- 

 riod with such vertebrae. However this may be, if the vertebrae 

 were caudal as supposed by Mr. Marsh, since they are about 2£ 



• The remains were discovered in 1855 though not published till 1861, 



