340 
ACTIXOPTERYGII. 
It is not improbable that the undefined name Caturus bucldandi 
(L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 1844, p. 119) pertains to this 
species. It was originally applied to a specimen from Lyme Regis 
exhibiting the head and anterior portion of trunk, but the present 
writer has not been able to discover this fossil. 
Form. <Sf Loc. Lower Lias : Dorsetshire. 
All the following specimens were obtained from the neighbourhood 
of Lyme Regis :—- 
38121. Head with abdominal region exposed from the left side, 
shown of one-half the natural size in PI. IX. fig. 1. The 
cranium is too much crushed for examination, and the 
facial bones are mostly imperfect and fractured. The 
short and deep premaxillae (pmx.) bear a few large slender 
teeth ; the maxilla ( mcc .) exhibits a close series of small 
slender teeth, and there is a supramaxillary bone ( s.rnoc .). 
The mandible exhibits very large, widely-spaced teeth in 
the dentary bone (<L), and there are indications of the 
ascending p]ate of bone behind the tooth-bearing margin. 
The form and proportions of the opercular bones (op., 
s.op., i.op., p.op.) are shown, while the large size of the 
upper branchiostegal ray (br. 1) and of the gular plate (g.) 
is noteworthy. The left post-temporal ( p.t .), clavicle, 
and supraclavicle are partly exhibited, and there are 
remains of the postclavicular plates. The pectoral fin is 
nearly complete ; its anterior rays are remarkably straight, 
and it appears to have been fringed with slender fulcra ; 
only four rays of the left pelvic fin remain, but the large, 
slender fulcra are well preserved. Of the dorsal fin, only 
some of the supports are shown. The position of the 
notochord is marked by a confused line of hypocentra and 
pleurocentra ; the ribs are long and the neural arches 
short, but both remarkably slender. Above the neural 
arches is a series of very robust, slightly bent, long bones, 
inclined backwards, commencing shortly behind the head 
and extending even beneath the supports of the dorsal 
fin ; and these appear to be the separate neural spines. 
All the scales are smooth, and their rhombic form is well 
shown in the dorsal region. Purchased , 1864. 
P. 897. Head and fragment of abdominal region shown from the 
right side. The dentition is indicated as in the last 
specimen. Egerton Coll. 
P. 4377. Remains of head and opercular apparatus in indurated 
Lias. Enniskillen Coll■ 
