Belonging to CorneU University. 251 



cc. Humeral process mucli longer and stronger than the coracoid 

 process ; lateral plates not meeting on the back in front of a point 



midway between the dorsal fins Doras Lacepede. 



bb. Eye in the middle or behind the middle of the head. 



Oxydoras Kner. 

 aa. Barbels not simple, maxilary and sometimes mental barbels fringed. 

 Eye large ; teeth rudimentary or absent. 

 d. Lateral scutes well developed from the dorsal plate backward. 



Hemidoras Bleeker. 

 dd. Lateral scutes rudimentary on the anterior half of the body or 

 none ; a svibdermal stay connects the dorsal plate with the tip of the 

 humeral process, a similar one connects the tip of the dorsal with the 

 post-temporal, to which the stay is firmly joined. Snout long and 

 pointed ; head compressed ; lower profile straight, upper profile 

 strongly arched. Humeral process broad, rounded behind. Numer- 

 ous pores in the axil giving a sieve-like appearance. 



Hassar E. & E, 



6. Doras dor!i$aliS Cuv. & Val. 1703, 1729, . Three speci- 

 mens. 



7. Doras spiiiosissiiiiiis E. & E. 1729. Brazil, 



8. Doras weddellii Castl. 1706, 1707, 1708, 1709, 1727. Marajo. 



9. Doras costatiis (Linn.) 1747. Trocero on Tocantins. 



10. Oxydoras niger (Yal.) 1700, 1701, 1719. Para. 



Analysis of the Species of Hcissar. 



a. Dorsal with a conspicuous black spot. 



b. Scapula covered with skin ; black spot on dorsal not extending to 



upper margin of membrane orestes (Steind.) 



bb. Scapula granular ; black spot extending to upper margin of mem- 

 brane ■wilderi sp. nov. 



aa. Dorsal without black spot ; dusky at tip affinis (Steind.) 



11. Hassar orestes (Steind.) 1733, 1734, 1735, 1736, 1737, 1741, 

 1742, 1743, 1744, 1745, 1746, 1747, 1748, Itaituba, Brazil. 



12. Hassar '%vilderi sp. nov. 



Body subterete, highest below the dorsal spine, tapering backward, the 

 depth everywhere greater than the width. Head rather loag ; higher than 

 wide, snout pointed, the profile not very steep from dorsal spine to the 

 eye, thence much steeper forward, the space in front of the anterior nostril 

 slightly concave. Bones of the head finely granular. 



Supraclavicle with its distinct dermal ossification not meeting the hu- 

 meral process, its surface finely granular. Fontanel narrow, as long as 

 the eye, its center over the pupil ; a bridge across its jjosterior half. 



Eye large, placed high and far back midway between posterior margin 

 of the dorsal plate and tip of the snout, measunng to the orbital rim 1| 



