532 REPORT OF THE COMMISSIONER OF FISHERIES. 
the recent bock by Knauthe (1901). These names have often been 
given specific value and were bestowed usually either for characters 
of the integument or of form (cf. Giinther, 1868, p. 26); thus we have 
such names as Cyprinus macrolepidotus, C. rex cyprinorum, C. specu- 
laris (for the mirror carp), C. nudus (leather carp), and C. cirrosus, 
C. regina, C. hungaricus, C. elatus, C. aeuminatus, ete., and C. hybis- 
coides, a variety with the fins much prolonged. This list of synonyms 
might be extended much further. 
Hessel (1881) considers all the varieties of carp as falling into threc 
chief groups, which he distinguishes as follows (op. cit., p. 867): 4 
1. Cyprinus carpio communis, the scale carp; with regular, concentrically-arranged 
scales, being, in fact, the original species improved. 
2. Cyprinus carpio specularis, the mirror carp; thus named on account of the extra- 
ordinarily large scales, which run along the sides of the body in three or four rows, 
the rest of the body being bare. 
3. Cyprinus carpio coriaceus, or nudus, the leather carp; which has on the back 
either only a few scales or none at all, and possesses a thick, soft skin, which feels 
velvety to the touch. ‘ 
Walter (Knauthe, 1901), however, says the scale, mirror, and leather 
carp must not be considered as distinct species or races, although the 
conditions of the scales are characteristic, since a similar differentiation 
of the scales, or at least a tendency to it, is found in every true race 
of carp. In many ponds where one of these forms (1. e., scale, mirror, 
or leather) has been raised, the others have appeared spontaneously. 
He concludes that they should be considered only as varieties. He goes 
on to say that the ordinary characters are so inconstant and variable 
that sharp lines can not be drawn between the various intergrading 
races. In his opinion, the division into races should depend princi- 
pally upon the relations in size of various parts or measurements of 
the body, though he correlates with this set of characters three others, 
viz, (1) rate of growth (i. e., the ability for rapid growth); (2) adapt- 
ability to climatic changes, and (3) time of sexual maturity. He then 
develops a rather artificial classification, depending mostly, as he says, 
upon the two ways in which the flesh is disposed upon the back; that 
is, whether there is a large development of the dorsal musculature, 
forming a highly arched outline, often with a hump and a reentrant 
angle back of the head, or whether the dorsal outline is low and com- 
paratively straight. He uses as a measure of this the ratio of the 
height of the body to the length. This ratio is designated by the 
letter V in the following classification, translated from his paper (p. 85): 
I. Cultivated races; V=1:2 to 1:3. 
(a) High-backed cultivated races; V=1:2 to 1:2.6. 
(6) Broad-backed cultivated races; V=1: 2.61 to 1:3. 
(I. Primitive and degenerate races; V=1:3.01 to 1:3.6. 
Here belong also those forms under the size ratio 1:2 to 1:3 which co not 
have a breadth in correspondence with their size ratio. 
a The blue carp, so called, is probably but a color phase, and not a true ‘‘ variety.” 
