70 THE WASATCH AND BRIDGER FAUN^. 



Dapedoglossus encaustus Cope. 



Balletin U. 8. Gcol. Surv. Terrs., 1677, p. 808. Osteoglo$»um enoauitum Cope, Annnal Report U. 8. GeoL 



8nrv. Terrs., 1870, p. 430. 



Plate VI, fig. 1. 



Eepresented by a portion of the side of a large individual, including 

 the series of scales bearing the lateral lines, and three series above and 

 three below it, more or less perfectly preserved. The longitudinal extent 

 of the fragment includes seventeen transverse series. These scales are of 

 large size, the included portions are smooth to the naked eye, but rugose 

 under the microscope, and with but few and faint traces of concentric lines. 

 Exposed portion with entire margin, bearing a large lenticular rugose sur- 

 face. This rugosity consists of elevated portions of an enamel-like mate- 

 rial, between small pits and gi-ooves. The septa between the cells are dis- 

 tinctly visible on the smooth part of the scale; on the rugose surface they 

 are represented by grooves. The cells are in curved series, which extend 

 to the center of growth, growing smaller as they converge. The rugose part 

 of the exposed surface diminishes in relative extent towards the anterior part 

 of the body. The tubes of the lateral line are in this species concealed 

 beneath the extenial layer of the scale. The opening is nearer the margin 

 than the center of the scale, is round, and is frequently accompanied by a 

 smaller one above and in front of it. 



MeasuremenU. 



M. 



Length of fifteen consecntive scales 23 



Depth of six longitudinal scries scales 127 



Vertical diaraeter of a scale 0^ 



Transverse diameter of a scale C25 



Diameter of a submarginal scale cell 001} 



Width of rugose nreii of scale Oil 



As compared with the species of Osteoghsswm, whose scales have been 

 figured, the present oflfers clear distinction. In 0. hicirrhosum, figured in 

 Agassiz and Spix Brazilian Fishes, Tab. XXV, the scales have distinct con- 

 centric grooves, and the rugosity consists of a few points or projections. 

 In 0. formosum, figured in Solomon Mueller's travels in Borneo, &c., the 

 rugosity is uniform on the exjioscd surface, and very minute, and there are 



