184 
ACTTNOPTEETGII. 
laminar expansion of one pelvic fin-support is distinct; 
and some of the bordering scutes on the caudal region are 
observed to be prolonged into the lath-shaped plates. 
Lewis Collo 
f 
Leptotrachelus hakelensis, Pictet & Humbert. 
1866. Leptotrachelus hakelensis, Pictet & Humbert^ Nouv. Rech. Poiss. 
Foss. Mont Liban, p. 98, pi. xiv. fig. 3. 
Type. Imperfect fish ; Geneva Museum. 
An'imperfectly known small species about 0*12 in length, with 
much attenuated rostrum. Anterior abdominal region short, and 
vertebral centra not more than twice as long as deep ; total number 
of vertebrae probably about 60. Length of head with opercular 
apparatus about equalling the distance between the pectoral and 
pelvic fins; distance between the pelvic and anal fins considerably 
greater. Dorsal and ventral triradiate scutes much attenuated. 
Form. ^ Log. Upper Cretaceous : Mt. Lebanon, Syria. 
P. 6001. Relatively large and well-preserved specimen, wanting 
the end of the tail; Hakel. The operculum seems to be 
nearly quadrangular in form, a little broader than deep ; 
and it is bordered below by a suboperculum of about half 
its depth. The vertebrae are shown, with traces of the 
very delicate dermal scutes ; and there are fragmentary 
remains of the pectoral, pelvic, and anal fins. Lewis ColL 
P. IBS'S". Smaller and more imperfect specimen, showing the form 
of the cranial roof ; Hakel. 
Presented hy Sir J. William Dawson.^ K.G.M.G.^ 1884» 
Leptotrachelus elongatus (Agassiz). 
[Plate XII. fig. 4.] 
1835. Fercetis elongatus, L. Agassiz, Poiss. Foss., Feuill. p. 55 (name 
only). 
1837-44, Fercetis elongatus, L. Agassiz, ibid. voL ii. pt. ii. p, 258^ 
pi. lxvi«. figs. 1, 2, 5-8 {non figs. 3, 4). 
1879. Fercetis elongatus, W. Davies, Geol. Mag. [2] vol. vi. p. 145. 
1888. Fercetis elongatus, A. S. Woodward, Proc. Geol. Assoc, vol. x. 
p. 318. 
Type. Imperfect fish ; British Museum. 
A slender species, probably attaining a length of about 0*6, but 
usually smaller. The postorbital region of the skull about as broad 
as long, this occupying the hinder quarter and the orbit the next 
