NATURAL SCIENCES OF PHILADELPHIA. 103 



and a quarter, and in all probabilities not fully grown. The body is slender 

 and subfusiform, quite compressed, deepest at the insertion of the ventrals, and 

 tapering towards the base of the caudal. The head is slender, subconical, and 

 rounded off anteriorly. The anterior undivided ray of the anal fin is quite 

 large, and a good deal more conspicuous than the second one. There are but 

 six articulated rays to that fin. The ground color is yellowish brown, macu- 

 lated with black or blackish brown. 



XXXVI. Specimens of a species of Boleosoma were collected by Dr. C. B. Ken- 

 nedy, under Lieut. A. W. Whipple, in the Rio Seco, Texas, and in the Rio Leona, 

 near Fort Inge, Texas. It is slender and graceful in general appearance, mea- 

 suring an inch and three quarters in total length, in which the head enters 

 about four times and a half. The first dorsal fin is longer and lower than the 

 second, and superiorly convex. The anal is much deeper than long upon its 

 base, and convex upon its edge. The tips of the ventral fins extend a little fur- 

 ther back than those of the pectorals. The rays are as follows : D x; 10 ; A 

 8 ; C 3, 1, 7, 1, 1, 3 ; V r, 5 ; P 13. The ground color is olivaceous yellow, 

 maculated with black or blackish brown. The second dorsal and the caudal 

 fins being as usual transversally barred. A longitudinal black streak may be 

 observed in advance of the orbits, and a vertical one beneath them. We call 

 the species Boleosoma gracile. 



XXXVII. Under the name of Boleichthys we have instituted a genus which 

 is intermediate between Boleosoma and Oligocephalus. The head is subconical, 

 tapering forwards, the jaws being nearly equal, hence the mouth is terminal, 

 slightly protractile, and of moderate size. The opercular apparatus is scaly, 

 whilst the cheeks and the throat are bare. The two dorsal fins are distinctly 

 separated ; the first being lower than the second. The anal is well developed, 

 although somewhat smaller than the second dorsal. The caudal is subtruncate 

 or subcrescentic. 



The typical species of this genus was collected by Dr. Geo. Suckley, under 

 Gov. I. I. Stevens, in Little Muddy river, a tributary of the Upper Missouri. It 

 is a very slender fish, measuring an inch and three quarters in total length. 

 The body is compressed, tapering towards the peduncle of the tail, which is 

 slightly contracted. The head constitutes a little less than the fourth of the 

 total length. The eye is large and subcircular, its diameter entering three times 

 and a half in the length of the side of the head. The posterior extremity of 

 the maxillar bone extends to a vertical line which would intersect the anterior 

 rim of the pupil. The formula of the fins is as follows : D x; 10; A n, 8 ; C 

 3, 1, 6, 6, 1, 3 ; V i, 5 ; P 12. The lateral line, from the orbit passes over the 

 opercular apparatus, keeping nearer the dorsal than the abdominal line to the 

 peduncle of the tail, hence midway to the insertion of the caudal, when it does 

 not disappear before reaching it. The pectorals extend further back than the 

 ventrals ; the first dorsal is convex. The ground color is yellowish brown, 

 maculated with greyish black. The dorsals and the caudal fin are transvers- 

 ally barred. A dark spot may be seen on the occipital region, and a streak in 

 advance as well as beneath the orbit. We call the species Boleichthys ezilis, on 

 account of its slender appearance. 



XXXVIII. A second species of Boleichthys, which we call B. whipplii, was 

 collected in Coal creek, Arkansas, by the party under Lieut. A. W. Whipple. 

 Its body is more compressed and proportionally deeper than in the foregoing 

 species. The head constitutes a little less than the fourth of the total length, 

 which is nearly two inches. The first dorsal fin is convex in its outline. The 

 ventrals extend further back than the pectorals. The rays of the fins are : D 

 ix ; 13 ; A ii, 8 ; C 2, 1, 8, 1, 1, 3 ; V I, 5 ; P 12. The scales are rather small, 

 smaller than in the preceding species, and the lateral line is but slightly nearer 

 the dorsal than the ventral line. The ground color is reddish brown, incon- 

 spicuously maculated ; a black spot may be observed at the scapular region. 

 The second dorsal and the caudal fins are transversally barred. 



1859.] 



