28 CAUFOUNIA ACADKMY OF SCIENCES 



roiindeil posteriorly. In tlic former case it is not infrequently continued iKickward 

 onto the dorsal plate. The j^ranulations are always very line; they are sonjetinies 

 arranjjed in series, and are always rather distant and inconspicuous. 



The teeth (ni the pMlatt' are especially v:irial)lc. Tlie vnniciiiir |i;ilciies ai'e 

 usually small, and may lie either conlluent with each other and with tin' palatine 

 patches, or niav he se|)arated from hoth by a *,n'oove. This variation seems to l)e not 

 determined hy aije. The palatine patches are sometimes ovale, small, with very 

 indistinct hackward processes; sometimes fully twice as large, pnidiiicd backward, 

 with their inner margins nearly straight and diverging. 



The snout is usually broadly rounded or subtruiicate, seen from above. In 

 some cases, however, it is sharply convex, the mouth then with more lateral cleft, 

 and often with swollen lips. In all the specimens, the premaxillary band of teeth is 

 long, its width being contained not le.-s than fuui' iImk's in the Icii^lli. The barbels 

 are always short, the maxillary barbel seldom reaching the gill-o[)enin,n. In adults, 

 the appearance is often peculiarly modified by the great enlargement of the upper 

 portion of the cheek muscles, making the top of the head transversely concave. 



The long adi|)Ose fin is highest near its middle, where the vertical height is about 

 one-third the length. The tin is not wholly adnate, there being a short, free posterior 

 border. It is constantly a little longer than the base of the first dorsal. 



43. Netuma platypogon {Gilnther). 



Abundant in the Panama market. Of the ten specimens preserved, six are 

 females, with elongate ventrals, which overlap the front of the anal. Unlike 

 G. eigemnnnni, the vent is constant in position, not more anteriorly placed in 

 females. As in G. eu/enmanni and G. jordani, the inner ventral ray is somewhat 

 broadened in females, and gives attachment to a dermal thickening, less marked, 

 however, in this species. 



In one male specimen taken at some date between January 10 and February 

 24, the mouth contained eggs, and was obviously functioning as a brood-cavity. 

 The strong arch to the buccal roof was evident. It is clear that the breeding season 

 is not confined to dune and July, as given by Steindachner (1876 b, p. 17). 



i\. ijl(dijp()(j(jn has the basal portion of the paired fins jet black on their upper 

 surfaces, in both males and females. The anal is blackish in its anterior two-thirds, 

 with a wide while margin. The fontanel groove is everywhere sharply defined. It 

 is widest a little in front of the middle of its length, tapering slowly liackward to the 

 ba.se of the occipital plate, the base of which is always reached. Anteriorly, it 

 narrows more rapidly, terminating in an acute point which is opposite or in advance 

 of the middle of the eyes. 



The dorsal spine is very narrowly compressed, its anterior margin sharp, 



strongly serrate. 



44. Netuma oscula {Jordan <i- Gilbert). 



Two specimens are distinguishable from N. planicept^ only by the smaller 

 mouth and the shorter band of premaxillary teeth. The width of the latter (antero- 



