152 
SELACHJI. 
Ptjjchudus papillosus, E. D. Cope, Yert. Cret. Form. West (U. S. 
Geol. iSurv. Tcrrit. 1875), p. 294. — Cretaceous ; Colorado. 
Ptijtihodus triunpularig, A. E. lleuss, Verstein. bohm. Kreideform. 
1845, pt. i. p. 2, pi. ii. figs. 14—19. Toetb very doubt- 
fully placed in this genus and referred to Acrodus by 
A. Fritsch, Kept. u. Fische bohm. Kreideform. 1878, 
p. 16, fig. 38. — Upper Cretaceous ; Bohemia. 
Piychodus wMppdeyi, J. Marcou, Geol. N. America, 1858, p- 33, 
pi. i. fig. 4; J. Leidy, Extinct Vert. Fauna West lerrit. 
(U. S. Geol. Snrv. Territ. 1873), p. 300, pi. xviii. figs- 
20; J. S. Newberry, Eep. Expl. Exped. from Santa Fe 
to Colorado, 1876, p. 137, pi. iii. fig. 2. — Cretaceous 
(Niobrara Epoch) ; Colorado, Kansas, New Mexico, U-S.A. 
M ith the Myliobatidse may also perhaps be associated the small, 
flattened, rhomhoidal teeth from the Upper Chalk of Maastricht, 
Holland, described under the name of lUiombodns hinkhorsti, 
W. Dames, Sitzungsb. Gesell. naturf. Freuude, Berlin, 1881, P- 
woodcuts. 
Family TRYGONlDiE. 
Pectoral fins uninterruptedly continued to, and confluent at, the 
extremit)’' of the snout. Tail slender, sharply marked off from the 
disk. Vertical fins absent or imperfectly developed, often re- 
placed by strong serrated spines. 
Genus TRYGON, Cuvier (“ ex Adanson ”). 
[Begne Animal, vol. ii. 1817, p. 136.] 
Genus T.ffi]>IIURA, Miiller & Henle. 
[Syst. Beschreib. Plagiost. 1841, p. 171.] 
The known fossil representatives of these two genera have not 
hitherto been exhaustively studied and described. Prof. Dr. Carl 
Hasso has made known * a detached vertebra, from the Low'er 
Chalk (Aptian) of Dizier, considered to bo referable to Tryyon or an 
allied genus ; E. Lawley ^ has referred a Pliocene dermal tubercle 
to a species named T. tair/ionii ; and several nearly comi)lete fishes, 
probably rightly placed here, have been discovered in the Middle 
Eoc.ene limestone of Monte Bolca, near Verona. One of the latter 
' IS'atiirl. Elasinobr., B.-eond. Tbcil, p. M-1. pi. xix. figs. 4, 5, 6. 
’ Nuovi Sliuli I’esca foss. Colline Tobcusic, 1870, p. 45, pi. ii. fig- 4. 
