PHYSOSTOMI. 
Pisces. 33 
PlagopterincB. The basin of the Colorado river is the habitat of this 
small group, composed of Plagopterus, Lepidomeda, and Meda. Pla- 
gopterus argentissimus, Cope, pi. xxvi. figs. 3 & 3 a ; Lepidomeda vittata. 
Cope, pi. xxvi. figs. 2 & 2 a, and L.jarrovii, Cope, figs. 1 & 1 a, figured ; 
Cope & Yarrow, 1. c. 
Misgurnus cestoideus, sp. n., Kessler, L c. p. 34, pi. iii. fig. v. Dalai Nor. 
Diplophysa dalaica, p. 24, fig. i., nasalisy p. 27, fig. 2, intermedia^ p. 28, 
fig. 3, and costata, p. 29, fig. 4, spp. nn., id. 1. c., Dalai Nor. 
Nemachilus robustus, p. 32, Chinese prov. Kansu, and zaidamemis, p. 34, 
Zaidam, spp. nn., id. 1. c. 
Diplophysa^ Kessler, ? = Nemachilus^ p. 793 ; N. yarlcandensis and 
tenuis, p. 796, Yarkand, gracilis, p. 798, head-waters of Indus, spp. nn. : 
Day, P. Z. S. 1876. 
j CyPElNODONTIDiK. 
Pantodon, g. n. Body similar in form to Haplochilus, with upper 
surface of head flat, and cleft of the mouth very wide and ascending ; 
body and head as far as the interorbital region covered with cycloid 
scales, lateral line distinct with curve towards the lower surface ; margin 
of the upper jaw formed in the middle by the single immovable inter- 
maxillary, laterally by the maxillary consisting of a single piece ; pointed 
teeth on the intermaxillary, maxillary, mandible, vomer, palatal, and 
pterygoid bones, on the sphenoid, the tongue, and the upper and lower 
pharyngeals ; gill-opening very wide ; gill-membranes touching one an- 
other and covering the isthmus; gill-covers consisting only of the 
operculum and the prseoperculum ; eleven branchiostegal rays, gills four, 
that of the first arch formed of a single row of gill-laminte ; infra- 
orbital ring complete ; pseudo-branchiae none ; fins naked, a short dorsal 
beginning in the middle of the tail, above the end of the moderately 
long anal ; first and last ray of pectoral undivided ; the middle rays, 
which are in small number, branched ; ventral fins elongate, consisting 
of one articulated undivided and five branched rays ; caudal fin elongate; 
with two articulated undivided rays above and below ; stomach horse-shoe 
shaped, with coecal sac ; a single pyloric appendage ; intestine short ; 
swimming-bladder of thin membrane, simple, without auditory ossicles ; 
generative organ with a duct. Type, P. buchholzi, sp. n., Peters, 1. c. 
p. 196, pi. figs. 1-4, Victoria River. 
/ Cynelebias, g. n. Cyprinodont: bones of each mandibulary firmly 
united; dorsal and anal many-rayed, the latter fin the longest and 
beginning before the dorsal ; a band of pointed teeth in both jaws, 
before which is a row of unequal large canines ; ventral i^all, a very 
little distance before the anal ; gill-openings wide, separate. C. porosus, 
sp. n., Steindachner, SB. Ak. Wien, Ixxiv. p. 172, pi. x. fig. 3, Pernam- 
buco. 
}/ Cyprinodonmartce, sp. n., id. op. cit. Ixxii. p. 610, Sta. Marta, at mouth 
of Magdalen River. 
^/Fundulus parvipin7iis, Gii\, moles descvihed ; id. op. cit. Ixxiv. p. 201, 
pi. X. figs. 1 & 2. 
