DISCUSSION OF SPECIES AXD THEIK DISTRIBUTION. 



453 



Tlie dorsal fin begins ni)on the snout in the perpendicular from the anterior margin of 

 the lower eye. It is composed of from !t9 to 104 simple rays (in 5 specimens), the longest 

 of whicli in the posterior fourth of the fin; their length (9) nearly half tlint of tlie head. 

 The anal fin begins between the tips of the ventral, close to the vent, and under tlie inser- 

 tion of the pectoral. It is composed of 70 to 84 simple rays, the hmgest in tlie posterior 

 fourth; their lengtli (7) slightly more than one-third the length of the head. 



The caudal is sessile, rounded, the middle rays in length (17) nearly double tlie longest 

 dorsal rays. 



The pectoral, present only on the colored side, is inserte<l close to the branched open- 

 ing, its length (15) three-fourths that of the head. 



The ventrals are upon the median ventral line, even in length (6), slightly shorter or 

 nearly eipial to the longest rays of the anal. 



Color on the left side ashy brown, -with numerous more or less distinct darker brown 

 spots. On tlic blind side white. Pectoral blackish, with traces of ligliter transverse bands. 

 Eadial formula: D. 9!t-103; A. 79-84. Lateral line, 92. 



•20 in curve. 



The young form of Monolene described by Goode under tlie name Thyris pellucidug 

 (Fig. ."3.59) is so remarkablj' di.stinct, that the description is given here: 



Tlie length of the specimen described (So. 26005) is 72 millimeters. 



The height of the body (32) is about one-third of its length (without caudal), the least 

 height of the tail (7) onefourteenth. The body is thin, pellucid, larval like, divided into 

 three longitudinal tracts by depressions at the bases of the rows of iiiter,s](iiions processes, 

 as in (llypUicipluiJiis. 



The scales are small, thin, easily detached (none remain upon the sjiecimeii except a 

 few in the lateral line). The number of transverse rows is estimated at 120, the number 

 of rows above and below the lateral line at the widest portion of the body 17 or IS. The 

 scales in the lateral line are jnovided with a large central canal. The lateral line is 

 straight on both sides. 



The heail is very small; its length (bS) contained about five and one-half times in the 



