50 TELEOSTEI : EVENTOGNATHI, — XII. 
epidermis. The fins and other parts are often charged with pig- 
ment, the usual color being red, but sometimes satin-white, yellow- 
ish, or black. 
Nore.— Young Cyprinide are usually more slender than adults of the 
same species, and the eye is always much larger; they also frequently show 
a black lateral stripe and caudal spot, which the adults may not possess. In 
the following descriptions, the rudimentary rays of dorsal and anal are not 
counted. The fins and scales are often, especially in specimens living in small 
brooks, covered with round black specks, parasitic plants. These should not 
be mistaken for true color-markings. 
No progress can be made in the study of these fish without careful attention 
to the teeth, as the genera are largely based on dental characters. The 
pharyngeal bones in the smaller species can be removed by inserting a pin (or, 
better, a small hook) through the gill opening, under the shoulder girdle. 
The teeth should be carefully cleaned with a tooth-brush, or, better, a jet of 
water, and when dry may be examined by any small lens. In most cases a 
principal row of four or five larger teeth will be found, in front of which is 
a set of one or two smaller ones. The two sides are usually, but not always, 
symmetrical. Thus, ‘‘teeth 2, 4-5, 1,” indicate two rows of teeth on each 
side, on the one side four in the principal row and two in the lesser, on the 
other side five in the main row and one in the other. ‘‘ Teeth 4-4” indi- 
cates a single row of four on each pharyngeal bone, and so on. 
In the Leuciscine genera, these teeth, or the principal ones, are ‘‘ rapta- 
torial,’’ that is, hooked inward at the tips. A grinding or masticatory surface 
is an excavated space or groove, usually at the base of the hook. Sometimes 
the grinding surface is very narrow and confined to one or two teeth. Some- 
times a bevelled or flattened edge looks so much like a grinding surface as to 
mislead a superficial observer. In some cases, the edge of the tooth is crenate 
or serrate. 
Besides the native species here mentioned, representatives of two other 
genera have been introduced from Europe, and have become inhabitants of 
some eastern streams. These are Cyprinus Linnzus, and Carassius Nilsson. 
The first is distinguished by the very long dorsal, which, like the anal, is pre- 
ceded by a strong spine, serrated behind. About the mouth are four long 
barbels, and the teeth are molar, 1, 3-3, 1. This genus is represented by 
the Carp (Cyprinus carpio L.). The carp is normally covered with large 
scales. In domestication, however, variations have arisen, prominent ones 
being the “ Leather Carp,’’ naked, and the ‘‘ Mirror Carp,” with a few series 
of very large scales. 
Carassius Nilsson differs from Cyprinus, chiefly in the absence of barbels, 
and in having the teeth compressed, 4-4. The Gold-fish (Carassius auratus 
L.) is originally olivaceous, but only the orange-red variety is valued for 
aquaria. Both Carassius and Cyprinus are native in China. 
a, Air-bladder surrounded by many convolutions of the very long alimentary 
canal, which is 6 to 9 times the length of the body. (Campostomine.) 
bd, Teeth 4-4, or 1, 4-4, 0, with oblique grinding surface and slight hook; 
peritoneum black (as usual in herbivorous fishes). CAmMPosToMA, 49. 
aa. Air-bladder wholly above (dorsal) of the alimentary canal. 
c. Alimentary canal elongate, more than twice length of body; teeth one- 
rowed, the grinding surface well developed, the hook usually slight 
or wanting ; peritoneum usually black. Species chiefly herbivorous. 
(Chondrostomine.) 
