380 
ACTINOPTERTGII. 
recurve 1 teeth in both jaws. The relatively great extent 
of the articulo-angular element of the mandible is 
distinct, while a few of the slender branchiostegal li! 5 9 
occur below. Tho clavicle is shown to be robust, and the 
pelvic fin-support expanded. Remains of an undigeste 
individual, apparently of Leptotrachdus gracilis, exten 
along the whole length of the abdominal region ; an 
there are some rounded bodies clustered in advance o 
the pelvic fins, which may be ova. Lewis Col . 
46524. Small imperfect fish, wanting the rostral end of the skull , 
Sahel Alma. ‘ Lewis Coll. 
47361-62. Two imperfect examples of the trunk ; Sahel Alma. 
Lewis Coll. 
The following specimen probably belongs to a large individual 
of Leptotrachdus triqueter, but its specific determination is un 
certain : — 
P. 1903, P. 4250. Vertically crushed skull and pectoral arch, in 
counterpart ; Sahel Alma. The rostral region and an 
impression of the remainder of the cranial roof exhibit an 
ornamentation of delicate raised lines and rows of sm a 
tubercles ; those on the mesethmoid in a longitudina 
direction, those on the hinder part of the frontal more or 
less radiating and scarcely reaching its posterior borer • 
The mandibular ramus of the left side is shown to e 
similarly ornamented with longitudinal series of fi° e 
tubercles. The slender teeth are clustered as usua 
Remains of the slender spaced branchiostegal rays ®J" e 
seen, about 12 on the left side. The right pectoral a 
exhibits 11 rays, all distantly articulated at the dis a 
end, and all except the first two bifurcating twice dista 
The anterior vertebral centra are not more than twice 
long as deep. Egerton <j- Enniskillen Co 
Leptotrachelus gracilis, Davis. 
1887. Leptotrachdus gracilis, J. W. Davis, Trans. Roy. Dublin Soc. [-J 
v °l- hi- p. 623, pi. xxxviii. fig. 3. 
L'ype. Nearly complete fish ; British Museum. .. 
A verj slender species attaining a length of about 0 - 5, but usua 
sma ler. Length of head with opercular apparatus contained a 
live and a half times iu the total length to the base of the cau a 
