30. CATOSTOMID2E 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.) 



67. UHNYTREniA Jordan. 

 Spotted Suckers. 



(Jordan, Mau. 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 plicre ou 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 fleshy portion 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 developed 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 tlje diameter of the eye. 

 Isthmus moderate. Pharyngeal bones essentially as in Moxostoma. 

 Body rather elongate, sub terete, 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 high, 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. Ventrals rather in advance 

 of vhe middle of the dorsal, their rays normally 9, rarely 8 or 10. Anal 

 fin high and short, often more or less emargiuate in males. Caudal flu 

 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.* (//tvy?, reduced ; r/> ?;//, aperture; in allu- 

 sion to the imperfections of the lateral line.) 



* M. austrinum Beau. Body rather stout, the depth 4 iii length. Head 4^- in length. 

 Lips plicate, truncate behind. Light hrown above, yellowish below ; some scales 

 brownish at base. Paired fins wilh dark blotches. D. 11; A. 6; scales G-44-G. Mi- 

 choacan, Mexico (west of Sierra Mad re). This species is probably a Minytrema, but 

 the air-bladder has been removed from the typical specimens. 



(Myxostoma auslrina Beau, Proc. U. S. Nat. Mus. 1879, 302.) 



