the Ophidium barbatum. 4 4-1? 
Pinna dorfalis longa * anali longior fed anguftior^ 
cum caudali continuata, ball fordide albefcens, mar- 
gine nigra e pun 61 is plurimis nigris Radii fim- 
plices., flexiles, molles. 
Pinna’ pedforales obovatae, pelhickke, membrane, 
pu noils mkrutiflamis irrorata. 
Pinna analis caudali unita, bad albefcens, niargine 
nigra, radii s fimplicibus. 
Pinna caudalis nigra, apice obtufa. 
Color capitis et corporis carneo-argen-teis. 
Lc. : A :: 85 : 35, Lc. : PI :: 85 :• 15 
Lc. : DI :: 85 : 27 Lc. : PF :: 85 : 22: 
Lc. : DFCFAF :: 85 : 87 Lc. AI :: 8.5 : 37 
R. 5k* P. 2. D. 2. 3. 4. 5. 6. A. 3.. 4. 5. 6. 
Before I proceed, I think it necefiary to explain the propor- 
tional meafures which I employed in the foregoing defcriptiom. 
artedi confdered the meafarement of fifties, as necefiary to. 
render the defcription of them perfedl ; and therefore in the 
fpecies which he defcribed mod; completely, we find, he did not 
fail to exprefs, with the greateh accuracy, the diftances between; 
the feveral parts. Fie has been followed in this by the heft 
authors who have written upon fifties, as gronovius and 
fallas. The like practice has been followed by fome writers 
in defcribing animals of other clafies ; and particularly by Mr. 
daubenton, who has, with extraordinary exadhiefs, exprefted 
the meafurements of quadrupeds. The ufe of this meafure- 
mcnt, however, can only afcertain that fuch or fuch individual 
is larger or lefs than another defcribed by an author : for it is. 
impoffible by fuch means to determine a fpecies, and therefore 
a fingle meamrement, taken from the head to the tail, or in 
* Pinna mihi audit longa, cujus bails longitudine.excedit radium altiorem. 
. 1 ' x fhort. 
