30. CATOSTOMID^ — MINYTREMA. 135 
tain lights the appearance of pale stripes along the rows of scales; fins 
dusky, especially at their tips. Elvers of Florida. 
(Jordan, Bull. U. S. Nat. Mus. xii, 148, 1878.) 
6^.— MSl^YTiiEyiA Jordan. 
Spotted SucJcers. 
(Jordan, Man. Vert. E. U. S. ed. 2, 318; type Catostomus melanops Raf. ) 
Head moderate, rather broad above. Mouth moderate, inferior, hori- 
zontal; the upper lip well developed, freely protractile; the lower rather 
small, infolded, /^-shaped in outline, plicate, with 12-20 idicm on each 
side. Lower jaw without cartilaginous sheath. Eye moderate, rather 
high, placed about midway of the head. Suborbital bones consider- 
ably developed, not very much narrower than the fieshy iiortion of 
the cheek below them; the posterior suborbital concavo-convex, about 
twice as long as deep, sometimes divided; the anterior somewhat deeper 
than long, often divided into two, sometimes united with the preorbital, 
which is well develojied and much longer than broad. The number and 
form of these bones, except as to their depth, are not constant in the 
same species, and do not afford specific characters. Opercular bones 
well developed, not much rugose. Fontanelle evident, rather large. 
Gill-rakers rather long, in length about half the diameter of the eye. 
Isthmus moderate. Pharyngeal bones essentially as in 2Ioxostonia. 
Body rather elongate, subterete, becoming deep and rather compressed 
with age. Scales rather large, nearly equal over the body, the radiating 
furrows not specially marked. Lateral line interrupted in the adult, 
but with perfect tubes, imperfect in partly grown specimens, entirely 
obsolete in the young. Scales in a longitudinal series 44-47 in number, 
12-14 in a transverse series from dorsal to ventrals. Dorsal fin rather 
short and higli, with about 12 developed rays, beginning rather nearer 
the snout than the base of the caudal. Pectoral fins moderate, not 
reaching ventrals, the latter not to vent. Yentrals rather in advance 
of ihe miildle of the ciorsal, their rays normally 9, rarely 8 or 10. Anal 
fin high and short, often more or less emarginate in males. Caudal fin 
moderately forked, the lobes about equal. Air-bladder with two cham- 
bers. Males in spring with the head covered with many small tubercles. 
One species certainly known.* (//cvu?, reduced ; T/)?7/jta, aperture; in allu- 
sion to the imperfections of the lateral line.) 
* M. aiistrinum Beau. Body rather stout, the depth! iu length. Head iu length. 
Lips plicate, truncate behind. Light brown above, yellowish below; some scales 
brownish at base. Paired fins widi dark blotches. D. 11; A. (i; scales G-44-G. Mi- 
choacan, Mexico (west of Sierra Madre). This species is x^robably a Minytrema, but 
the air-bladder has Ijeen removed from the tyxiical specimens. 
t^Myxostoma austrina Beau, Proc. U. S. Nat. Mus. 1879, 302.) 
