the Ophidium barbatum. 441 
Pinna dorfalis longa * anali longior fed anguftior, 
cum caudali contmuata, bafi fordide albefcens, mar- 
gine nigra, e puncHs plurimis nigris : Radii firm 
plices-, flex lies, molies. 
Pinnae pectorals s obovatas, pellucidas, membrana. 
punctis mmutifiimis irrorata. 
Pinna analis caudali. unita, bafi albefcens, margin©, 
nigra, radiisfimplicibus. 
Pinna caudalis nigra, apice obtufiu. 
Color capitis et corporis carneo-argenteus. 
Lc. : A : : 85 : 35 Lc. : PI :: 85 : 15 
Lc. : DI :: 85 : 27 Lc. : PF :: 85 : 22 
Lc. : DFCFAF :: 85 : 87 Lc. : AI :: 85 : 37 
r - 5 t* 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 meafu res which I employed in the foregoing defcriptiom 
artedi confidered the meafurement of fifties as necefiary to 
render the defcription of them perfect ; and therefore in the 
fpecies which he defcribed moft completely,. we find, he did not 
fail to exprefs, with the greateft accuracy, the diftances between 
the feverai parts. He has been fallowed in this by the beft 
authors who have written upon fifties, as gronovius and 
Pallas. The like practice has been followed by fome writers 
in defcribing animals of other clafies ; and particularly by Mr.' 
daubenton* who has,. with extraordinary exaftnefs, exprefied 
the meafurements of quadrupeds. The ufe of this meafure- 
ment, however, can only afcertain that fucli 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 meafurement, taken from the head to the tail,, or in 
* Pinna.mi.hi audit longa, c.ujus balis longitudine excedit radium altiorem. 
ftiort 
