OBSERVATIONS ON FISH SCALES. 
139 
elongate), L. leschenaultii (looks like T. ariza, but differs by strong basal radii, which are entirely absent 
m T. ariza), L. bata (quite like T. ariza, with no basal radii), L. pangusia, L. nigripinnis, L. kawrus, 
L. microphthalmus . Several others approach the same type quite closely, and it is evident that so far 
as the scales go, Tylognathus can not be separated from Labeo. 
Varicorhinus Ruppell. Proc. Biol. Soc. Wash., xxiii, p. 148. 
Xenocypris Gunther. Zool. Anzeiger, xxxvi, p. 253, fig. 5 ( X . argentea). I have two species from the 
British Museum, both having pale subcircular scales. 
Scale about 5X mm. long and 5 Abroad; laterobasal comers rounded; no basal radii; circuli in inter- 
radial (apical) region strong, transverse; nucleus almost central (Kiu-Kiang; Styan). 
_ t X. microlepis 
Scale about 3% mm. long and 3 % broad; laterobasal comers more evident; no basal radii; apical 
radii 7 or 8, the interradial circuli transverse, strong, widely spaced; nucleus far basad of 
middle (mountain streams near Kiu-Kiang; Styan). X. argentea Gunther 
In the apical field there is a strong resemblance to Chondrostoma, but that genus has well- 
developed basal radii. See also Zool. Anzeiger, xxxvm, p. 86. 
Zacco Jordan & Evermann. Zool. Anzeiger, xxxvm, p. 86, fig. 4. 
CATOSTOMIDE. Suckers and buffalo-fishes. 
The scales of the Catostomidae are usually quite large, and resemble those of the Old World Cyprinidae 
in most respects. For figures see Proceedings Biological Society of Washington, volume xxn, page 158, 
figure 2 ( Catostomus griseus ; the figure is printed upside down); Biological Bulletin, volume xx, plate 1, 
figure 3 ( Moxostoma aureolum), and figure 4 (Pantosteus santa-ance). In every case the basal radii are 
well developed. The scales of Moxostoma cervinum Cope, showing two types, one reticulated, are 
described in Science, July 28, 1911, page 126. 
Subfamily ICTIOBINE. Buffalo-fishes. 
In the carp sucker, Carpiodes velifer (Rafinesque), the scales from just below the front of the dorsal 
fin are broader than long, but those from between posterior end of dorsal and lateral line are longer than 
broad. The scales studied are from a fish about 4 pi inches long, from the Wabash River, Indiana 
(Bureau of Fisheries). Apical margin broadly rounded; laterobasal angles distinct; base rounded, 
forming a single broad lobe, between which and the laterobasal angles the margin is concave; circuli 
very distinct, in the apical field only about half as closely set as laterally and basally; apical radii few, 
usually three, one median, and a curved one on each side, but sometimes five are present; basal radii 
numerous, about 30, or more counting imperfect ones, close together; nucleus central or almost. Latinu- 
cleate scales are coarsely and irregularly reticulate in the middle. Compared with the Catostomine 
series, this falls with Catostomus commersonii, from which it is at once separated by the character of 
the apical radii. 
Subfamily CATOSTOMINE. Suckers. 
Scales very small; oval, oblong, or subcircular, without laterobasal comers. 1 
Scales larger, often very large, with evident laterobasal comers.. 4 
1. Radii all around; nucleus more or less apicad of middle (Boulder County, Colo.). 
Catostomus griseus (Girard) 
Radii apical and basal, the lateral basal ones usually not pointing to the nucleus, but when 
complete strongly crooked above, the bent basal end then pointing to the nuelcus; nucleus 
central or basad of center. 2 
2. Nucleus nearly central, or moderately basad of middle. 3 
Nucleus far basad of middle of the very small scales (Russian River, Cal.; Stanford University. 
Catostomus occidentalis Ayres 
3. Scales often broader than long, but variable (Oregon).C. macrocheilus Girard 
Scales longer than broad, but little different from the last (California). .C. humboldtianus Snyder 
Scales closely resembling the last, but with lateral circuli more developed, so as to approach 
C. griseus, except for the more basad nucleus (California). Pantosteus santa-ance Snyder 
(The tubercles in the upper lip are much more numerous in the Pantosteus than in 
Catostomus macrocheilus.) 
