50. PLATTNEMATICHTHYS. Ill 



1. Piramutana piramuta. 



Bagrus piramuta, Kner, Sitzungsber. Wien. Acad. xxVi. p. 382. 

 Piramutana piramuta, Bleek. I. c. 



B. 12-13. D. 1/6. A. 14. P. 1/10. 



Head nearly as high as broad, its greatest width being two-thirds 

 of its length. Eye small, in the middle of the length of the head, 

 directed upwards. The occipital process extends one-quarter of the 

 length of the head further backwards than tbe margins of the occiput, 

 nearly to the basal bone of the dorsal spine, and is almost as broad 

 behind as at its base. The teeth on the vomer form a band, which 

 is separate from those of the palatines. , Dorsal spine striated, not 

 serrated, shorter than the dorsal rays, which are one-third lower 

 than the body. Pectoral spine slightly serrated interiorly, as long 

 as the first soft rays and as the rays of the dorsal fin. Ventrals as 

 long as pectorals ; adipose fin nearly twice as long as anal. Caudal 

 deeply forked, with the upper lobe produced into a filament. The 

 maxillary barbels extend to below the adipose fin, the outer ones of 

 the mandible beyond the middle of the pectoral. {Kner.) 



Barra do Bio Negro and Borba Rio Madeira. 



2. Piramutana blochii. 



Silurus clarias, Bl. taf. 35. figs. 1, 2 (not L.). 



callarias, part., Bl. Schn. p. 379. 



Pimelodus blocnii, Cuv. fy Vol. xv. p. 188. 



Arius albicans, Cuv. fy Vol. xv. p. 80; Valeric, in a" Orb. Voy. Atne-: 



Merid. Atl. Poiss. pi. 3. fig. 2. 

 Ariodes clarias, Midi, fy Trosch. Hor. Ichth. iii. p. 10. 

 Pseudariodes clarias, Bleek. I. c. 



D. 1/6. A. 10-11. 



The maxillary barbels extend beyond the ventral fins. Adipose 

 fin twice as- long as the anal. The teeth on the palate form a patch 

 on each pterygoid bone, and there is sometimes another pair of very 

 small patches on the vomer. Back light brown, with darker spots ; 

 a silvery band along the lateral line ; sides below the band spotted 

 like the back. 



Guiana, Brazils. 



50. PLATTNEMATICHTHYS*. 



Platynematichthys, Bleek. Nederl. Tydschr. Dierk. 1863, p. 99. 



Adipose fin of moderate length ; a short dorsal fin with a strong 

 spine and with six soft rays; anal fin short. Barbels six, broad, 

 band-like. Yomer with a band of villiform teeth. Jaws equal in 

 length. Eyes with a free orbital margin ; skin not reticulated, 

 covering the whole of the upper surface of the head and neck. Cau- 

 dal forked ; ventral with six rays. 



Brazils. 



* 1. ? Galeichthys araguayensis, Casteln. Anim. Amir. Sud, Poiss. p. 37. pi. 17. 

 fig. 3. — Araguay. 



