258 
the teeth continue in triple, then double series, which becomes, 
single on the posterior half of the jaw. The palatal teeth form 
in front an uninterrupted erescent of three series, which gra- 
dually decrease, and terminate on the vomer in a single series. 
The teeth of the lower jaw are distributed in a manner simi- 
lar to those of the upper , except on the symphysis, where both 
clusters generally coalesce behind, and are merely separated in 
front by a notch. But individuals occur, in which both bran- 
ches are separated bij a naked longitudinal interval. The gin- 
giva is very lax and studded with papillulae. 
The interval between the maxillary- and the vomero-pala- 
tal teeth, is filled up by the gingiva, which renders the teeth 
indistinct, and makes the upper jaw appear, as if it t(hrough- 
out was armed with several series of teeth. The fleshy tongue 
is elongated, conical with a rounded flattened apex. The up- 
per surface, during life, is flattened, with several longitudinal 
wrinkles. In specimens preserved in spirits of wine, the up- 
per surface becomes contracted, and presents a longitudinal 
furrow. The tongue extends to the symphysis of the jaw and 
is provided with a lax fraenulum. As observed by Mr. Jonan- 
NES Mürren (Myxinoïden 1. c.), there is a small blind fossa, 
apparently without sac, between the upper extremity of the 
hyoid bone and that of the anterior branchial arch. On each 
side of the pharynx appears a small oval fleshy tubercle, and 
behind it a second, studded with numerous minute card-like 
teeth. Immediately behind the middle of the posterior bran- 
chial arch, appear a few similar teeth, accompanying the 
arch. The branchial arches are osseous, slender, with short, 
dense, single branchiae. The gillmembrane is lax and un- 
divided; the posterior, free margin extends transversely across 
the throat, but it does not ascend the sides. The gillope- 
ning thus appears like a low arch, with the convexity for- 
wards. ‘The external surface of the membrane is marked with 
Jongitudinal farrows, corresponding to the five lowest pairs 
of branchiostegous rays. The latter are all short, compressed 
like the blade of a sabre, osseous at the basal half, the other 
