T40 
bulletin oe the bureau of fisheries. 
4. Lateral and apical (interradial) circuli about equally far apart, strictly transverse 5 
Apical circuli conspicuously more widely spaced than lateral 6 
5. Scale subcircular, about 4% mm. diameter, with about 4 to 6 apical, and 17 to 20 basal (no lateral) 
radii (Little South Fork, Cumberland River, Ky. ; P. H. Kirsch), 
Lagochila lacera Jordan & Brayton 
Scale smaller, rather more quadrate, with very prominent laterobasal angles; radii very strong, 
apical 4 to 6, basal 6 to 8 (Cherokee, Iowa; S. E. .Phcopharynx duquesnii (Le Sueur) 
6. Basal radii very numerous, 12 in young scales, up to 20 or more in adult; center reticulated in 
latinucleate scales Catostomus commersonii (Lacepfede), including C. teres Mitchill 
Basal radii less numerous 7 
7. Basal radii more than 12; scale hardly differing from C. commersonii, but interradial circuli 
more arched Erimyzon sucetta (Lac6pMe) 
Basal radii about 7 to 9 in normal scales 8 
8. With many incomplete apical radii Moxostoma cervinum (Cope) 
With at most one or two incomplete apical radii Minytrema melanops (Rafinesque) 
The scales of several of the above, but especially those of Lagochila, are quite of the type of Chon- 
drostoma. It is evident that the scales of the American Catostomidas can be practically matched among 
the Palasarctic and Oriental Cyprinidas, excepting only the western small-scaled group of Pantosteus and 
Catostomus griseus, occidentalis , etc. Even this exception is doubtful, for these smaller scales are cer- 
tainly extremely like those of Oreinus, from Yunnan, Nepal, Assam, etc. It thus seems entirely impos- 
sible to find a scale character separating the Catostomidse from the Old World Cyprinidae. Decactylus 
Rafinesque, type Decactylus commersonii (Lacepede), or if Lacepfede’s fish is considered dubious, Decac- 
tylus teres (Mitchill), seems to be a valid genus, but Catostomus occidentalis, macrocheilus, etc., must be 
excluded from it. 
COBITIDiF. Loaches. 
Subfamily COBITIN^. 
The scales of this subfamily have been discussed in Proceedings of the Biological Society of Wash- 
ington, volume XXII, pages 205-206. The following genera are available for examination: 
Cobitis Linnaeus. T. c., p. 206 (C. tcenia). 
Misgurnus Lac6pMe. T. c., p. 206 {M.fossilis, M. anguillicaudatus) . 
Somileptes (Swainson) Bleeker. T. c., p. 206 {Cobitis gongota). 
Lepidocephalichthys Bleeker. T. c., p. 206 (L. berdmorei and L. guntea). 
Acantkopsis Van Hasselt. A. chcerorhynchus (Bleeker) from Meetam, Tenasserim (Fea; B. M.) has 
scales which are much broader than long, with radii all aroimd ; transverse diameter less than half a 
millimeter. The scales are of the same general type as those of Cobitis tcenia, and entirely different 
from the elongated scales of Somileptes and Lepidocephalichthys . 
Subfamily HOMALOPTERINiE. East Indian loaches. 
For Gastromyzon and Homaloptera (pi. xxxiv, fig. 17) see Proceedings Biological Society of Wash- 
ington, volume xxn, pages 206-207. 
KNERIIDE. 
Proceedings Biological Society of Washington, volume xxm, page 113; Biological Bulletin, volume 
XX, plate v, figure 31. {Kneria cameronensis Boulenger). This family falls here in Jordan’s list, but 
in his two-volume work no justification for this position is fotmd. Boulenger, having examined the 
skeleton of K. cameronensis, places the family between Phractolaemidae and Cromeriidae. Regan (1911) 
places it near to Chanidae, or milk fishes. It is an isolated type, and its scales are very peculiar. 
Suborder GYMNOTI. Electric eels. 
Dr. Max Ellis has in preparation a detailed paper on the scales of this group. He has very kindly 
allowed me to examine his series of slides in order to state the principal characters. Greatly to my sur- 
prise I find the scales to be quite different from those of the characinids known to me, but very similar 
