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318 ROY L. MOODIE 
such as Trematops, and Cacops.? Some, such as Eryops? 
and Diplocaulus, have imperfectly developed lateral line canals, 
in the form of interrupted, shallow grooves, and others such as 
Trimerorhachis® have the lateral line canals sharply incised. 
Doctor Williston suggests therefore that the group represented 
by Trematops and Cacops are purely land-living amphibians. 
Eryops and Diplocaulus are transitional types which live partly 
in, partly out of, water and that Trimerorhachis is a strictly 
aquatic type. With the aquatic habit in Trimerorhachis goes 
a peculiarly interesting development of the pectoral girdle which 
is very like the pectoral girdle of the large labyrinthodonts, 
Mastodonsaurus,® and its allies. 
This observation of Williston’s agrees well with those of Kings- 
bury’ on the temporary loss of the lateral line organs in Diemyc- 
tylus on. leaving the water for breeding purposes. It also 
agrees well with the loss of lateral line organs in the metamorpho- 
sis of the tadpole of the frog and in Salamandra. 
If the occurrence of lateral line organs indicates an aquatic 
habit for the animals possessing them, as seems entirely possible, 
then the fauna described by Wiman (’14) is aquatic, for the lateral 
line canals are unusually distinct and with this sharp incision of 
the lateral line canals goes a pectoral girdle consisting of corru- 
gated clavicles and interclavicles which is entirely similar to the 
same elements in Mastodonsaurus and Trimerorhachis. The 
species described by Wiman are all new and in view of the im- 
3 Trematops: Jour. Geol., vol. 17, no. 7, pp. 6386-658, figs. 1-6, 1909; Cacops : 
Bull. Geol. Soc. Amer., vol. 21, pp. 249-284, pls. 6-17, 1910. See also: Revision 
of the Amphibia and Pisces of the Permian of North America. Publication No. 
146, Carnegie Institution of Washington, 1911; Jour. Geol., vol. 22, no. 1, pp. 57- 
70, figs. I-11, 1914. 
4 Jour. Morph., vol. 19, no. 2, pp. 521-525, figs. 9-11, 1908; ibid., vol. 23, no. 1, 
pp. 31-48, pls. 1-2, 1912; Revision of the Amphibia and Pisces of the Permian of 
North America, by E. C. Case, publ. 146, Carnegie Inst., pp. 15-31, pls. 1-10, 
1911; Transactions Kansas Academy Science, 1909. 
5 Jour. Geol., vol. 21, no. 7, pp. 625-627, 1 fig., 1913. 
6 Paleontographica, Bd. 36, pp. 1-158, pls. 1-17, 1889; ibid, Bd. 60, pp. 275- 
294, Tafin. 16-22, 1913.; Fiihrer durch das kel. Naturalien-Kabinett zu Stuttgart, 
1906, by E. Fraas. 
i Proceedings Amer. Microscop. Soc., vol. 17, p. 130, 1895. 
