1856.] 199 



13. Cyprinella lugubris. Elongated, fasiform ; head large and mouth ac- 

 cordingly, though the latter is smaller than in C. macrostoma. The ventrals are 

 inserted under the anterior margin of the dorsal. Dark brown above, silyery 

 upon the sides and under the belly. 



The locality were this species was collected is not precisely known. It was 

 brought borne by Lt. E. G. Beckwith. 



14. Cyprinella ludibunda. All the specimens of this species which we have 

 examined are immature, and yet there is no doubt in our mind as to its specific 

 difference from all the species hereto alluded to. The head is small and conical, 

 with the snout round and truncated. The mouth being small. The ventrals 

 inserted in advance of the anterior margin of the dorsal. Color reddish brown ; 

 middle of sides silvery; lateral line marked with black dots. 



Associated with the preceding, and collected under the same circumstances. 



"We next introduce a genus composed of small species, all being provided with 

 scales similar in general outline, to those of both Plargyrus and Cyprinella : we 

 call it 



MONTANA. 



Its species truly replace the Plargyri in a more southern latitude under a 

 diminutive aspect. As regards structure, they differ widely from Plargijrus, as 

 will appear by the following diagnosis : Body compressed, subfusiform. Head 

 rather small, subconical or rounded. Snout occasionally protruding slightly. 

 Mouth suboblique, terminal ; both jaws generally equal. No barbels. Isthmus 

 narrow. Eyes moderate. Caudal fin bifurcated. These characters, so far, are 

 found in Plargyrus. But now for the differences. The insertion ofthe ventrals is 

 situated in advance of the anterior margin of the dorsal, which is higher than 

 long. The pharyngeal teeth are compressed, of the raptatorial kind, of the 

 hooked type, without grinding surface, instead of which, a sharp ridge is observed, 

 very minutely crenated. They are disposed upon a single row of four, thus : 

 44. 



Besides a species previously described, there are several new ones to be placed 

 on record. 



1. Montana lutrensis Leitcisms lutrensis, B, & G. in Marcy^s Expl. of Eed 

 Riv. of La. 1853, 251. Zool. PI. xiv. figs. 912. 



From Otter creek, tributary of the northern fork of Red River, Ark. It was 

 also caught in Gypsum creek, a tributary of the false Washita River, by H. B. 

 MoUhausen, under Lt. A. W. Whipple, U. S. A. 



2. Montana lecnina. The largest of the hitherto known species of the genus. 

 The entire length measures three inches and a quarter, the head forming the 

 fourth of it, the caudal fin excluded. The body is very deep upon its middle, 

 where the greatest depth is a little less than the fourth of the entire length. The 

 mouth is proportionally small. The eye being circular, its diameter entering four 

 times in the length of the side of the head. The rays are : 



D9 + 2;A10 + 2; 5,1,9,8,1,7; V9; P 16. 



Greyish brown above; white or dull yellowish beneath. 



Specimens were collected in Leon River, a tributary to the Rio San Antonio, 

 Texas, by Dr. C. B. Kennerly, under Lt. A. W. Whipple, U. S. A. 



3. Montana deliciosa. This is one of the most slender of all the species 

 hitherto known of the genus. Its length is a little over two inches and a half, 

 the head forming the fifth part of it. The latter is proportionally small, sub- 

 conical anteriorly. The eye is quite large and circular, its diameter en- 

 tering about three times in the length of the side of the head. There are ten 

 longitudinal rows of scales upon the greatest depth of the body ; the scales them- 



