384 NEW-YORK FAUNA. 
on their slender margins, uniting posteriorly below the edge of the lower lip, leaving them 
free above. Eyes distinct, lateral, and covered with the common teguments, 0*05 in diame- 
ter, and placed in a depression over the margin of the lower lip ; they are distant 0°2 from 
the end of the snout. ‘Temporal orifice large, and surrounded by a raised margin ; contracted, 
linear in front, circular behind; it is placed on the summit of the head, 0°15 anterior to the 
eyes. The branchial furrow is half an inch long, directed obliquely downwards, and extends 
to a point above the lower angle of the lateral lips; the apertures are exceedingly small, and 
appear to be capable of being closed by their membranous edges. Vent a large longitudinal 
aperture, 1°3 distant from the tip of the tail. 'The fins appear to be nothing more than mere 
membranous prolongations of the skin, without the slightest vestige of rays. The dorsal 
commences 1°6 distant from the tail, and 0°3 anterior to the vent, in a scarcely perceptible 
furrow, and advances low and subequally until about the middle of its length, when it begins 
to rise, and then rapidly diminishes at the tip of the tail, but at no point exceeds 0°1 in 
height ; anterior to its origin, is an obsolete furrow, extending 0-7 towards the head. The 
dorsal unites with the caudal and anal, which latter is obsoletely triangular, and becomes 
insensibly effaced at a point 0°6 posterior to the vent. 
Color, Of a nearly uniform dark or dusky brown, occasionally verging to bluish, somewhat 
lighter beneath ; the anterior part of the head darkest. 
Length, 4°0. Depth, 0°3. 
This species, which is common in most of the muddy streams of the northern and western 
districts, varies in thickness from that of a common earth-worm to the size of a swan’s quill. 
[ have lately received specimens through the kindness of Mr. Z. Thompson of Burlington, 
Vermont, who obtained them from Lake Champlain. It resembles the A. branchialis of 
Europe, although much larger, and is very distinct from it by its single dorsal. Its popular 
name in this state is Lamper Eel. Iam not aware that it is used for any other purpose than 
as bait for other fishes. 
