Cope.] J-^^ [Jan. 5, 



PLiECOSTOMUS ASPIL0GA8TER Sp. DOV. 



Head with three obtuse angles ; the lateral extending posterior to the 

 orbits ; the median obscure between the orbits, bat distinct on the occipi- 

 tal plate. Belly covered with granular scales which are collected into 

 indistinct scuta posterior to the lip. Posthumeral ridge short, covering 

 only four or five scuta. Besides this, the scuta are not keeled, 

 but are distinctly angular on the dorsolateral and ventrolateral rows, 

 and traces of keels exist on the anterior scuta of the two median 

 lateral rows. Occipital plate bounded posteriorly by two scuta which 

 are obtusely angulated, and these are separated from the base of the dor- 

 sal spine by three transverse nuchal plates, each of which has an obtuse 

 lateral angle of the surface. There is a naked patch on the end of the 

 muzzle, which does not reach the superior surface. Eye small, entering 

 length of head eight times, muzzle five times, and interorbital space 3.75 

 times. Lateral line of scuta, 30. All the scuta are rough with longitu- 

 dinal ridges, but they are not very spinous. Inferior and superior sur- 

 faces of caudal peduncle flattened. Length of head entering total (with- 

 out caudal fin), three and one-third times. 



Base of dorsal fin equal space between its posterior ray and a point half 

 way between adipose and caudal fins. First dorsal ray equal length of 

 head ; shortest caudal rays equal from end of muzzle to posterior border 

 of orbit. Radii, D. I. 8 in three specimens, I. 9 in one ; P. I. 6 ; V. L 5 ; 

 A. 5. Pectoral extending to basal third of ventral ; ventral to posterior 

 border of anal. Teeth |§ on each side the terminal portion elongate, 

 amber-colored. Length of median caudal rays .66 of length of head. 



Total length, 250 mm.; length to base of caudal fin, 198 mm.; to base of 

 anal, 122 mm.; to base of ventral, 82 mm.; to base of pectoral, 41 mm. 

 Length of head to posterior border of occipital plate, 54 mm.; width of 

 head at opercular fissure of lateral angle, 49 mm. Length of specimen 

 with dorsal radii I. 9, 275 mm. 



Color above, dark brown, spotted anteriorly with dusky ; below un- 

 spotted light brown. There are two or three dusky spots on each scuta, 

 but these are not visible posterior to the dorsal fin. The head is closely 

 spotted with very small dusky spots, which are large and more distinct 

 on the supralemporal region, where they have a diameter of about a milli- 

 meter and are separated by spaces of about the same diameters. The 

 dorsal fin is coarsely spotted with dusky, there being one or two rows on 

 each interspinous membrane. The pectorals, ventrals and anal are simi- 

 larly spotted, with a single row between the spines, and the caudal fin is 

 unspotted. 



In general proportions, and in the fin and scale formula, this species 

 resembles the P. commersonii, but in various other respects it apparently 

 resembles the P. carinatus of Steindachner. It difl'ers from this sjiecies 

 in the very obscure or absent carination, in the much smaller eye, and in 

 the shorter base of the dorsal fin, according to its describer. It is from 



