32 MONOGRAPH OF THE FRESH WATER IIL. 
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feature not being exhibited in the figure. The insertion of the ventrals takes place 
in advance of the anterior dorsal, and behind the base of the pectorals. The two 
inner rays are the longest, as seen in the enlarged figure of these fins beneath Fig. 
1. They do not reach the anus when bent backwards. The pectorals are of 
medium size, shorter than the head, composed of twelve unbranched rays. The 
membrane is deeply notched on the outer edge of the seven lowermost rays. Their 
base of insertion is nearly straight. When bent backwards they scarcely reach the 
anterior margin of the second dorsal, and leave the anal behind. 
18505 Gy ID) ayantin—ale, AN Te, (0) 2h Bo 4 i a, Wig Be IP 1 
The lateral line is slightly inflexed on the abdomen, but runs straight along the 
back until the posterior extremity of the second dorsal, when the fall takes place 
obliquely towards the centre of the peduncle of the tail, and straight again to the 
base of the caudal. The series of pores commences under the tenth ray of the 
second dorsal. 
The anus is situated a little nearer the end of the snout than the extremity of 
the caudal fin, consequently nearer the base of that fin than the snout. 
The color is thus described by Prof. Haldeman : “ yellowish, clouded with black, 
the first dorsal fin edged with a narrow line of orange.” 
The following information respecting the habits of this species, is from the 
notes of Professor Baird :— 
These fish usually inhabit clear, spring waters, especially the spring runs 
which flow through rich meadows, bordered by turf, and having a shallow pebbly 
bottom. They le concealed under projecting clods, flat stones, boards, or what- 
ever may serve their purposes of concealment. On being disturbed, they usu- 
ally hasten off to fresh cover, but sometimes remain motionless. Occasionally 
they occur in larger bodies of water, of less purity; but we have never seen them 
in creeks or rivers. Sometimes they are seen lying close to the edge of rivulets 
formed by leaking embankments, and where the water is far from clear. They 
always he close to the bottom, and are never seen poised in the water. 
The eggs are laid from the middle of April to the end of May, and are deposited 
in round packets about the size of an ounce bullet, under boards, stones, and in 
shallow, springy water. It is possible that they are watched by the parent, as we 
have frequently found individuals under the same cover as the eggs. The ova are 
of a rose color, and about the size of No. 3 shot, conveying the impression of dis- 
proportionate size. Occasionally, we have found the eggs with embryos moving 
freely within the envelope. A set examined April 22d, 1848, had the eye very dis- 
tinct, and of large size. The foetal fin extended from the head, by the tail, to the 
anus. In the course of the day, many became liberated, and swam about with 
the yolk bag attached. This was sessile, and filled with a transparent, reddish 
liquid, excepting opposite to the embryo, where was a hard, yellowish cake. All 
our attempts at raising the young, or of development of the egg, failed for want 
of fresh spring water. 
The body is the most slimy amongst the known species, whence its name visco- 
sus, which we think is well appropriated. Specimens have been collected by Prot 
