THE OATFISHES OiF ^•ENiEZUELA SCHULTZ 



317 



planiceps (Meek and Hildebrand). L. mystacinus has the lower lobo 

 of the caudal blackish, but in L. maracaiboensis the lower lobe of the 

 caudal is the same as rest of the fin, barred and without a pale posterior 

 edge; L. caucanus has only 10 or 11 plates from the anal to the caudal 

 fin base, 7 plates from dorsal to adipose origin, while the new species 

 has 12 or 13 and 5 or 6, respectively; L. planiceps has seven scutes 

 from dorsal to adipose, and pale spots on the membranes between 

 the rays of the dorsal, while in maracaiboensis there are five or six 

 plates and no pale spots on the membranes of any of the fins, the pale 

 spots occurring on the rays instead; L. mayoloi appears to be closely 

 related to maracaiboensis in regard to number of spines and plates, 

 but the new species has the lateral line pores conspicuously white 

 not shown on drawings or mentioned in descriptions of mayoloi or 

 any other species of Lasiancistrus . 



Named m.aracaiboensis for the basin in which it was taken in many 

 localities. 



Table 20. — Counts recorded for species of Lasiancistrus 



Genus HEMIANCISTRUS Bleeker 



Hemiancistrus Bleeker, Nederl. Tijdschr. Dierk., vol. 1, p. 78, 1863. (Type 

 Ancistrus medians Kner.) 



HEMIANCISTRUS MARACAIBOENSTS, new speciea 



Cajalo 

 Plate 10, C 



Holotype. — U.S.N.M. No. 121012, a specimen, 285 mm. in standard 

 length, collected by Leonard P. Scliultz near the mouth of the Rio 

 Concha in Lago Maracaibo on May 2, 1942. 



Paraiypes (all collected by L. P. Schultz).— U.S.N.M. No. 121014, a 

 specimen 200 mm. in standard length, from an isolated muddy pool 



533749—43 10 



