406 ANNALS OF THE CARNEGIE MUSEUM. 



below: breast and belly in front of the ventrals naked. Scutes meeting 

 along the mid-ventral line behind the ventrals: width of the head 

 I.I to 1.25 in its length, eyes lateral. Frontal fontanel small, making 

 a small niche in the occipital, reaching the level of the pupil in front. 

 Snout naked beyond the suborbitals, bluntly conical, more perpen- 

 dicular in front in young than in old specimens. Rictal barbels equal, 

 reaching the vertical from the middle of the eye. those of the lower 

 lip short. Mouth small and inferior. 



Scutes entirely covering the sides. Four scutes meeting on the 

 back just behind the dorsal: three azygous plates in front of the 

 adipose. Scutes somewhat roughened over the surface and along 

 the edge. 



Origin of the dorsal a little nearer the snout than the caudal. Dorsal 

 spine straight and well developed, about 1.2 in the head; a little 

 rough in front, finely toothed behind, the first two rays very little 

 longer than the spine. Pectoral spine half the diameter of the eye, 

 longer than the dorsal spine, equal to the head, otherwise like the 

 dorsal spine, reaching the second scute in front of the tips of the 

 ventrals. Adipose spine very slightly curved. Anal spine weak, 

 rough. Anal just reaching the lower caudal lobe. Ventrals short. 

 [.51 : -- ;-. :he distance from their base to the anal. Caudal the 

 diameter of the eye longer than the head. 



Top of head, back, and upper part of sides dark, yellowish below. 

 The dark color of the head, especially in smaller specimens, due to 

 numerous scattered chromatophores, small on the snout, larger near 

 the dorsal spine; the color of the sides due to a dark brown stripe, 

 along the iistal half of each scute, more distinct near the lateral line, 

 diffuse near the dorsal line on the upper plates and vanishing near 

 the ventral line on the lower plates. Opercle with light blue irides- 

 cence, which sometimes extends on to the humeral plate. Fins all 

 unmarked, except the ventrals, which are slightly dusky. 



Corydoras armatus 'Giinther). (Plate XXVII, fig. 3.) 



CaMchthys armatus G€~kther, Proc Zool. Soc. London, 1868, 230, fig. 1 (Xeberos 

 and Huallaga). 



CM. Two, 44 and 45 mm. San Joaquin, Sept. 5, 1909. Coll. 

 Haseman. 

 - _ C. M. Four, 54 to 61 mm. San Joaquin, Sept. 6, 1909. Coll. 

 Haseman. 



