KHIZODOXTIDiE. 
363 
P. 5482-84. Three typical small specimens, the third showing 
portions of the vertebrae in the abdominal region. 
Purchased , 1888. 
P. 5976-78. Portions of large individuals. Purchased, 1889. 
The two following genera are proved by their dentition to pertain 
to the Rhizodontidce, but are as yet too imperfectly known for 
precise definition. 
Genus CRICODUS; Agassiz. 
[Poiss. Foss. vol. ii. pt. ii. 1841, p. 156, pi. H. figs. 9-12.] 
Svn. Poluplocodus, C. H. Pander, Saurodipt., Dendrodont. &c. devon. 
Syst. I860, p. 28. 
Bones of fronto-ethmoidal shield fused into a single piece. Teeth 
rounded in section, with a large pulp-cavity. [Exposed portion 
of scales probably tuberculated.] 
Cricodus incurvus (Duff). 
1842. Dendrodus incurvus, P. Duff, Geol. Moray, p. 68, pi. vi. fig. 11. 
1844. Cricodus incur vus, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 162 
(name only). 
1844. Cricodus incurvus , L. Agassiz, Poiss. Foss. Y. G. R. pp. 61, 88, 
pi. xxviii. figs. 4, 5. 
Type. Tooth ; (?) collection of James Powrie, Esq., Beswallie. 
The type species, founded upon a small, stout, recurved tooth 
about 0-013 in length. 
Form. Loc. Upper Old Bed Sandstone: Scat Craig, Elgin. 
Upper Devonian: Riga. 
Not represented in the Collection. 
Cricodus wenjukowi, Rohon. 
1860. Polyplocodus incurvus, C. H. Pander {errore), Saurodipt., Dendro¬ 
dont. &c. devon. Syst. pp. 82, 84, 86, pi. x. fig. 23, pis. f, g, pi. l. 
figs. 1-5. 
1880. Dendrodus hiporcatus, H. Trautscliold {errore), Verhandl. russ.- 
kais. mineral. Ges. [2] vol. xv. p. 139, pis. iii.-v. 
1889. Cricodus ( Polyplocodus ) wenjukowi, J. V. Rohon, Mem. Acad. 
Imp. Sci. St.-Petersbourg, [7] vol. xxxvi. no. 14, p. 49, pi. i.figs. 3, 
4, 6, 11, pi. ii. figs. 12, 14, 19. 
(?) 1889. Dendrodus hiporcatus, J. V. Rohon {errore), ibid. p. 49, pi. i. 
figs. 1, 9. 
1890. Cricodus, H. Trautschold, Zeitschr. deutsch. geol. Ges. vol. xli. 
p. 629, pis. xxiii.-xxv. 
