162 
actinoptekygii. 
holm, Forhandl. vol. xv. (1893), p. 574. — Pleistocene; 
SkattmansG, Upland, Sweden. 
Osmerus albyi, H. E. Sauvage, Ann. Sci. Geol. vol. iv. (1873), 
art. no. 1, p. 215, fig. 53.— Upper Miocene; Licata, 
Sicily. [Imperfect fish.] 
Osmerus (Vacliiardi, de Bosniaski, Atfci Soc. Tosc.— Proc. Verb, 
vol. i. (1878), p. xix (name only). — Upper Miocene; 
Gabbro, Tuscany. 
Osmerus larteti, H. E. Sauvage, loe. cit. 1873, p. 213, fig. 41, and 
Joe. cit. vol. xi. (1880), art. no. 3, p. 40, fig. ll.— Ibld ' 
[Ditto.] 
Osmerus propterygius, H. E. Sauvage, ibid. p. 216, figs. 54, 62. 
Ibid. [Ditto.] 
Osmerus scarabellii, I. Bonomi, Rivista Ital. Paleont. vol. ii. (1893), 
p. 218, pi. v. fig. 6. — Upper Miocene; Mondaino, Pro 7 - 
Eorli, Italy. [Ditto.] 
Osmerus (?) stilpnos, II. E. Sauvage, loc. cit. 1873, p. 218, fig 8 - 0> ’ 
63. — Ibid. [Ditto.] 
The generic determination of these supposed species of Osina >‘ s 
is very doubtful. 
Family HALOSAURIDiE. 
Trunk much elongated, the caudal rogion relatively large and 
tapering. Parietal bones in contact, excluding the supraoccipha 
from the cranial roof ; squamosals suturally united with parietal* 
and completely covering the otic region ; snout a little produced ; a 
suborbital series of enlarged cheek -plates bearing the well-developed 
slime-canal. Mandibular suspensorium inclined forwards, and 
gape of mouth small ; premaxilla chiefly forming the upper border 
of the mouth, but maxilla also entering it ; teeth minute or rudi- 
mentary. Opercular apparatus incomplete, with numerous well- 
spaced slender branchiostegal rays, but no gular plate. Vertebral 
centra in the form of thin cylinders pierced by the notochord ; riba 
very short. Intermuscular bones present. Fin-fulcra absent; fin- 
rays bifurcated slightly and articulated at wide intervals in the 
distal half; pectoral fins placed well upon the flank, and pelvic fins 
well-developed, abdominal ; a single dorsal fin about the middle ot 
the back ; anal fin much extended, sometimes confluent with the 
caudal, Scales thin and cycloid ; lateral line conspicuous along the 
ventral portion of the flank. 
This family survives only in the deep sea, where it is represented 
by Halosaurus and one or two other closely related genera. A® 
