278 AIR-BREATHERS OF THE COAL PERIOD. 



In Fig. 65 I have represented a group of scales from the throat 

 of Dendrerpeton, as they lie beside the skull from which the 

 greater part of the details in Fig. 54 are taken. It will be seen 

 that these are elongated, oval, and very closely imbricated in rows 

 diverging in a pinnate manner from a mesial line. They would 

 give much protection, while not deficient in flexibility. It is pro- 

 bable however that Dendrerpeton could breathe by other means 

 than the gulping of air by the contraction of the throat ; and 

 would therefore be less dependent on the action of the gular mus- 

 cles than the modern batrachians. 



EXPLANATION OF PLATE VI, FIGS. 47, 48 and 54 to 56. 



Additional Reptilian Remains. 



Fig. 47 — Tooth of unknown reptile or fish, natural size, section natu- 

 ral size, and portion of section magnified, showing infold- 

 ing of the enamel and arrangement of the dentine. 



u 48— Small segment of another tooth similar to the last in form 

 and size, but more complex in the folding of the enamel' 



" 54 — Outer figure — Diagram of skull of Dendrerpeton, showing its 

 size and general form, the appearance of the occipital 

 condyles, and the arrangement of the double row of max- 

 illary teeth and of the vomerine teeth. 



" 54 — Inner figure — Diagram of skull of Hylonomus, showing the 

 arrangement of the single row of maxillary teeth and the 

 patch of palatal teeth. 



" 55 — Bony scales of the throat of Dendrerpeton JLcadianum, natural 

 size. 



XII. Invertebrate Air-Breathers. 

 Plate VI., Figs. 49 to 53, and 56 to 61. 



In addition to the insect whose eye has already been noticed, 

 but two species of land Invertebrates have been recognized in the 

 coal of Nova Scotia. One of these is a snail, Pupa vetusta, the 

 other a gally-worm or millepede, Xylobius sigillarice. They are 

 represented in the figures referred to at the head of this section, and 

 have been fully described in the Journal of the Geological Society 

 of London. 



The first is the oldest known representative of the land 

 snails, and so closely resembles the modern "chrysalis shells" of 



