PHYSOSTOMI. 
Pisces. 29 
vessel enclosed in bone, and those in which it is free. Day, P. Z. S. 
1876, p. 794. 
Lophiosilurus, g. n. Head very large, broad and extremely depressed ; 
cleft of mouth very wide, with prominent lower jaw ; teeth in the inter- 
maxillary and lower jaw, none on vomer or palatal bones ; a barbel at 
the angle of the mouth, four on the lower jaw ; nostrils small, far apart ; 
branchiostegal membranes separate, attached to isthmus in front only ; 
dorsal and adipose fins very little elevated, the first with a short strong 
spine, the last separated from the caudal. L. aleccandri, sp. n., Stein- 
dachner, 1. c. p. 164, pi. xv. Amazons. 
Silundia syJcesi ( ? = Ageniosus childreni, Sykes), p. 569, Deccan, 
& S. g angelica^ p. 670, Bengal and Burma, spp. nn., Day, J. L. S. xii. 
Platystoma paraliyhce, Steindachner, 1. c. p. 640, pi. ix. Brazil ; P. 
luetkeni, id. op. cit. Ixxii. p. 609, pi. xiii. Amazons : spp. nn. 
Pimelodus (Pseudorrhamdia) brasiliensis ?, p. 608, pi. vii., hartti, p. 611, 
(Rhamdia) parahyhce, p. 615, Brazil, {P seudorrhamdia) wesseli, p. 614, 
Essequibo, (^Rhamdid) hneri^ p. 631, Marabitanos, cayahm^ p. 633, 
Cayaba, spp. ,nn. ; descriptive and critical remarks on other species : 
Steindachner, pp. cit Ixxiv. pp. 698-632. Pimelodus {Pseudorrhamdia) 
chagresi\anus']^ sp. n., id. op. cit. Ixxii. p. 584, Panama. 
Pimelodus altipinnis, Stein., redescribed and figured ; id. 1. c. p. 606, 
pi. xi. 
Pimelodus pictus^ p. 144, agassizi, p. 147, id. op. cit. Ixxiv. Amazons, 
spp. nn. 
Pimelodus (Pimelodina, g. vel subg. n.) flavipinnis, sp. n., id. 1. c. p. 160, 
pi. xiii. fig. 2, Amazons. 
Rhamdia bransfordi, sp. n., Gill, P. Ac. Philad. 1876, p. 337, 
P'anama. 
Pirinampus agassizi, sp. n., Steindachner, SB. Ak. Wien, Ixxii. p. 607, 
pi. xii. Para. 
y ConorrhyncJius glaber, sp. n., id. op. cit. Ixxiv. p. 637, pi. viii. Brazil. 
Arius grandoculis, id. 1. c. p. 644, pi. xi. Brazil ; A. alatus, p. 569, 
pi. vi., brandtif p. 671, pi. iii. hessleriy p. 674, pi. v., planiceps^ p. 576, 
pi. iv., fuertlii, p. 679, hypophthalmus^ p. 581, pi. x., id. op. cit. Ixxii. 
Panama : spp. nn. 
jElurichthys panamensis^ Gill (A. nuchalis^ Gthr.), described and 
figured, p. 564, pi. ii. figs 1-4 ; A. pinnimaculatus, sp. n., p. 565, pi. viii. 
figs. 1-3, Panama : id. op. cit. Ixxii. J 
>/ Pseudauchenipterus jeguitinhonce^ p^ 647, pi. vi. figs. 1 & 1 a, affinis^ 
p. 651, striatuluSf p. 656, pi. v. Brazil, glaber, p. 655, Demerara, spp. nn. ; 
id. op. cit. Ixxiv. 
V Wertheimeria^ g. n. Head broad, depressed, long, with greatly 
lengthened cephalic buckler ; gill-oponing extending beneath the head ; 
gill-membranes confluent with isthmus in the middle under the throat ; 
dorsal short, one spine and six rays ; barbels six, cylindrical ; teeth in 
intermaxillary and lower jaw brittle; palate toothless; eye small, 
covered with membrane, over the cleft of the mouth and b^ehind the 
posterior nostrils ; ventral vertically behind dorsal. W. maculata, 
sp. n., id. 1. c. p. 660, pi. x. Rio Jequitinhonha. 
