PALAOZOIC ROCKS IN CANADA AND SCOTLAND. 379 
ARABELLITES CERVICORNIS, Hinde. (Pl. XIX. figs. 8 & 12.) 
Jaws very variable in form, sometimes crescentiform, with a short 
angular extension in front, at other times elongated and extended 
below the middle of the jaw; in front there are from two to three 
relatively large divergent teeth, followed by a series of from four to 
seven minute acute teeth. Length 3 line. 
ARABELLITES PECTINATUS, Hinde. (Pl. XIX. fig. 11.) 
Jaw rudely triangular, the front portion rounded, pointed poste- 
riorly, the sides meet below to form a short blunted extension nearly 
below the centre of the jaw; the upper border slightly arched, and 
carrying about fifteen small teeth, those in front rounded and up- 
right, the others acute and directed backwards. Length 3 line. 
ARABELLITES CRENULATUS, Hinde. (Pl. XIX. fig. 9.) 
Main portion of jaw nearly straight, flattened, and gradually 
tapering; in front is a short blunted rod-like extension at right 
angles to the toothed part of the jaw, which carries eight stout 
teeth, the first of which is small and claw-shaped, the others tri- 
angular and acute. Length ? line. Abundant. 
ARABELLITES QUADRATUS, Hinde. (Pl. XIX. fig. 14.) 
Jaw composed of a nearly square, slightly convex plate, with a 
blunted rod-like appendage projecting obliquely from one of the 
lower angles; on the upper, nearly straight, edge of the plate is a 
series of about fifteen small, subequal, rounded teeth or crenulations, 
whilst just below the upper edge, on what appears to be the posterior 
side, there 1s a small spur-like tooth projecting obliquely. Length 
of the toothed edge ? line. 
This is a very abundant species, and generally very regular in 
form, though varying considerably in size, some examples being 
nearly as large again as the specimen figured. 
ARABELLITES SCUTELLATUS, Hinde. (Pl. XIX. fig. 16.) 
Upper portion of the jaw subquadrate, with a prolonged, gradually 
narrowing base; surface slightly convex, with a very prominent pro- 
tuberance at the lower posterior angle: the nearly straight upper 
border carries eleven teeth, of which the first is pointed, somewhat 
longer than the rest, and projects outwards; the others are subequal 
rounded teeth. Length and width each about 3 line. Abundant. 
ARABELLITES? oBLIgUUS, Hinde. (Pl. XIX. fig. 15.) 
Jaw composed of a comparatively thick, obliquely semioval, concave 
plate ; the lower rounded edge is slightly elevated, the straight upper 
border has about fifteen small rounded subequal teeth or crenulations. 
Length 7 line, width 3 line. 
