84 
SELACHII. 
Belemnobatis sismondse^ ThioUiere. 
1864. Belemmbatis simnondce, V. TliiolliSre, Poiss. Foss. Bugey, pt- *• 
p. 8, pi. iii, fig. 1. 
1873, Belemnobatis sismondes, V. TMolliere, op. cit. pt. ii. (edit. P. 
yais), p. 12, pi. i. fig. 1. 
Type. Complete skeleton. 
Snout moderately obtuse ; tail shorter than disk. Dermal tuber- 
cles largest between the pelvic fins ; of considerable size along the 
median line of the back and on the anterior portion of the disk. 
Form. ^ Loc, Lower Kimmoridgian (Lithographic Stone) : Cirin, 
Ain, France. 
Genus ASTERODERMUS, Agassiz. 
[Reeh. Poiss. Foss. vol. iii. p. 381.] 
Disk elongate, gradually passing into the tail. Pectoral fins ex- 
tending forwards as far as the nasal capsules. Most preaxial ray 
of pelvic fin apparently of great size. Tail with two smooth dorsal 
spines j disk and tail covered with numerous stellate dermal calcifi- 
cations. 
This genus is placed by Hasse among the IlajidiB. 
Asterodermus platypterus^ Agassiz. 
1843. Asterodermus 2>latyptfrus, L. Agassiz, Poiss. Foss. vol. iii. P- 
pi. 44. figs. 2-0. ’ 6 > 
1860. Asterodermus platyptcrus, II. von Meyer, Palffiontogr. vol. vii. 
p. 9, pi. i. fig. 1. 
1861. Asterodermus platypterus, A. Wagner, Abb. k. bay. Akad. Wiss. 
math.-phys. Cl. vol. ix. p. .311. 
1882. Astcrodermm platxjpteni.s, C. Hasse, Natiirl. Syst. Elasm., Besond. 
Theil,p. 106. > . J 
Type. Skeleton, wanting cephalic region ; Mus. Geological Society 
of London. 
Snout produced and acute. Second dorsal spine somewhat smaller 
than the first, the former being at ono fourth the length of the tail 
from its extremity, and the latter being another fourth in advance. 
Dermal tubercles largest upon the region of the head and the pec- 
toral girdle. 
Form. ^ Loc. Lower Kimmeridgian (Lithographic Stone) : Kehl- 
heim, Bavaria. 
Family RAJID^. 
Disk broad, rhombic, generally with dermal asperities ; no barbed 
caudal sjjine ; tail with a longitudinal fold on each side, median fins 
varying in development. The pectoral fins extend to the snout. 
No electric organ in the living forms, except an occasional rudiment 
in the tail. 
