EUGXATHIDJE. 
329 
the preceding species, but very doubtfully distinct from the latter 
although made the type of another genus ( Isocolum ) by Egerton. 
The specimen is not much smaller than no. P. 3655 recorded above, 
but its vertebral elements and scales are both less robust. The 
suboperculum is deeper in proportion to its width ; and the striated 
character of the hinder half of the scales appears to be more 
general. 
Form. 4' Loc. Lower Lias : Dorsetshire. 
P. 3653. The type specimen described and figured by Egerton, Joe. 
cit .; Lyme Regis. The operculum is somewhat deeper 
than broad and completely covered with granulations, 
which are coarsest near the superior margin. The ossifi¬ 
cations in the notochordal sheath are confined to separate 
pleurocentra and hypocentra ; and the thick, sigmoidally- 
bent neural spines in the abdominal region are not fused 
with their comparatively delicate supporting arches. The 
ribs are short and delicate, while the neural and haemal 
arches in the caudal region are especially robust. The 
slender fulcra on the dorsal and pelvic fins appear to be 
biserial. The squamation is very little disturbed, and the 
narrowing of the scales on the ventral aspect is well 
shown; many of the principal flank-scales are finely 
denticulated. Enniskillen Coll. 
Genus CATURUS, Agassiz. 
[Reues Jahrb. 1834, p. 387.] 
Syn. Ureeus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 1833, p. 12 (non 
Urceus, Wagler, 1830). 
Conodus , L. Agassiz, ibid. vol. ii. pt. ii. 1844, p. 105 (name 
only). 
Strobilodus, A. Wagner, Abk. k. bay. Akad. Wiss., math.-phys. 
Cl. vol. vi. 1851, p. 75. 
Endactis, Sir P. Egerton, Figs. & Descript. Brit. Organic 
Remains, dec. ix. (Mem. Geol. Surv. 1858), no. 4. 
Thlattodus, R. Owen, Geol. Mag. vol. iii. 1866, p. 55. 
Ditaxiodus, R.Owen, ibid. p. 107. 
Trunk elongate-fusiform. External head-bones and opercular 
bones feebly ornamented with rugae and tuberculations, all except 
the cheek-plates robust; snout obtusely pointed, and maxilla 
straight or with a slightly concavely-arched dentigerous border; 
teeth relatively large and arranged in a sparse series on the margin 
