158 FISHES FROM GUAYMAS EVERMANN AND JENKINS. 



76. Upeueus rathbuni sp. uov. 

 (No. 4:5-Jll, U. S. Natiomil Miiscnuii.) 



Plate ii. 



I 



Head, 3A (4f ) ; depth, 4 (5); D. VIII-I, 8; A. I, 6 ; scales, 2.^-4l-G. j 

 Body slender; dorsal outline well arched ; profile from snout to origin 

 of first dorsal legularly curved, except above the eyes, where it is very 

 slightly flattened ; from first dorsal to posterior end of second dorsal ; 

 gently convex, and froui there to the caudal slightly concave ; ventral j 

 outline nearly straight to caudal fin; head triangular; snout blunt- i 

 pointed ; least depth of caudal peduncle 2^ in head, and its length IJ j 

 in the same; mouth slightly oblique; the maxillary, which is 3^ iu | 

 head, greatly broadened behind, almost reaching anterior margin of j 

 orbit; preorbital deep and broad, its dei)th 3h in head; lower jaw 

 slightly included; barbels moderate, scarcely reaching posterior edge 

 of opercles; i)reoi)ercle very weakly serrate. Eye large, 2^ in head, or i 

 lA in snout. First dorsal spiue minute, the second, third, and fourth I 

 subeiiual, H in head, the others decreasing gradually, the eighth being 

 contained less than 3 times in head; longest soft dorsal ray 2^ in | 

 head; anal spine evident; longest anal rays 2;j in head; pectorals 1| ' 

 in head, reaching posterior edge of spinous dorsal ; veutrals equal the , 

 pectorals. Scales large, ctenoid ; head well scaled, there being three I 

 scales upon the maxillary bone, a row of six upon the cheek, and an 

 odd one on its lower margin; preopercle and opercle with about two ! 

 rows each ; preorbital without scales, but roughened by a very evident j 



set of irregularly radiating lines, thus, ^_0<j(^; the branches of the 



pores in the scales of the lateral line are large and numerous, as many ! 

 as thirteen being counted in some scales. Teeth villiform, in a band • 

 broadest in front and narrowing backward. Gillrakers slender, the i 

 longest 3.i in maxillary, about 16 below the angle. Peritoneum black, j 



This species is allied to U. irreorhltaliH Smith & Swain, from which 

 it ditters in the slightly shorter head, greater dei)th, deeper caudal 

 peduncle, shorter maxillary, larger eye, wider interorbital, much nar- 

 rower preorbital, longer veutrals, slightly longer pectorals, the outline 

 of the spinous dorsal, the more numerous scales, and iu not having the 

 lower jaw produced. 



It seems to be related also to U. vamcolensu (Cuv. & Val.), but 

 may be distinguished from that species by the slightly longer head, 

 greater depth, shorter and deeper caudal peduncle, much shorter maxil- 

 lary, larger eye, narrower interorbital, slightly longer snout, smaller 

 scales, and in having the ventral line straight. 



One specimen 1!)4 millimetres in total length We have named this 

 species for Prof. Richard Rathbun, assistant in charge of scientific 

 inquiry, U. S. Fish Commission. 



i 



