310 ME, C. TATE REGAN ON THE 



from the caudal equal to \ the length of the middle rays of that fin ; adipose fin 

 represented by a membrane connecting the spine posteriorly to the caudal peduncle. 

 Distance from tip of snout to base of first dorsal ray 2-g times in the total length, from 

 base of last anal ray to caudal C-J- times. Greyish ; caudal with seme dark spots. 



Total length 82 mm. 



A single specimen from Villeta, Colombia, 3500 feet ; collected by Mr. Kay Thomson. 



2. Akges boulengeki, sp. n. 



Stygogenes hurnboldtii (non Swainson) Bouleng. Proc. Zool. Soc. 1887, p. 276, pi. xxi. fig. 2. 



Length of head about 3f times in the total length. Interocular width much less 

 than the distance from eye to posterior nostril, about 5 times in the length of head. 

 Lateral teeth of the outer series of the preemaxillaries unicuspid, median teeth bicuspid ; 

 mandibulary teeth bicuspid ; barbel extending to gill-opening. First dorsal ray nearly 

 equal to the length of head ; pectoral spine extending to posterior -§- of ventral ; 

 ventrals originating well in advance of the dorsal, extending |- of the distance from 

 their base to the anal opening ; spine of adipose fin well developed, freely movable, 

 inserted at a distance from the caudal equal to \ the length of the middle rays of that 

 fin. Adipose fin represented by a membrane connecting the spine posteriorly to the 

 caudal peduncle. Distance from the tip of snout to the base of first dorsal ray 

 2-g— 2f times in the total length, from the base of last anal ray to the caudal 5f times. 

 Brownish ; dorsal with some dark spots on the rays ; caudal with dark spots forming 

 3-4 cross-bars. 



Total length 70 mm. 



Three specimens from Canelos, Ecuador, collected by Mr. C. Buckley. 



3. Arges guentheri. (Plate XXI. fig. 2.) 



Stygogenes guentheri Bouleng. Arm. Mag. Nat. Hist. (5) xix. 1887, p. 348. 

 Cyclopium guentheri Eigenm. & Eigenm. Occ. Pap. Cal. Ac. i. 1890, p. 350. 



Length of head 3^-3-f times in the total length. Interocular width 3-J — 3-J times in 

 the length of head and nearly equal to the distance from eye to posterior nostril. 

 Outer series of teeth of the prsemaxillaries more or less club-shaped, with a pointed 

 lateral cusp, which is smaller and nearer the base in the lateral teeth than in the 

 median ; mandibulary teeth bicuspid ; barbel extending f-f of the distance from its 

 base to the gill-opening. First dorsal ray equal to § the length of head ; pectoral 

 spine extending to middle of ventral ; ventrals originating below the first dorsal ray, 

 extending to or beyond the anal opening; spine of adipose fin well developed, freely 

 movable, inserted at a distance from the caudal equal to f—f the length of the middle 

 rays of that fin. Adipose fin represented by a membrane connecting the spine 

 posteriorly to the caudal peduncle. Distance from tip of snout to base of first dorsal 



