208 Dr. B. Dowler on Viviparous Fish in Louisiana. 



removal of the enclosed foetuses it weighed only seven grains, 

 though not disemboweled. Thorough desiccation would pro- 

 bably reduce its weight one-half or more. The fish exposed for 

 two hours in the shade on a damp day, was but slightly desic- 

 cated. It was weighed by Mr. Macpherson, apothecary, in my 

 presence; but fearing a mistake, 1 had it weighed a second 

 time, with the same result. If each foetus weighed but one 

 grain, the aggregate would be more than three times that of 

 the mother. 



Measurements in inches : — Length, including the caudal fin, 

 2 inches ; greatest circumference, 1 1 ; width vertically, \ ; length 

 of thoracic fin, J : the caudal fin does not expand from its base 

 or proximal end, but terminates ovally ; its length, \ ; the anal, 

 but little expanded, ^ ; the ventral is too minute for convenient 

 measurement, being almost invisible without a lens; the dorsal, 

 which is single, has but a slight vertical width, arising from a 

 base ^ of an inch, nearly opposite, though a little forward of the 

 anal. 



The teeth are advanced, nearly ranging with the lips, being 

 very numerous, close and small, though scarcely discernible 

 without a magnifying glass. Lips thin, the under one slightly 

 projecting ; angles of the mouth not depressed. Eyes medium 

 size. Head flattened at the frontal bone. Operculum much ex- 

 panded. The branchiae largely developed in three great arches, 

 densely fringed with thick tufts, the outer and inner rows in- 

 clining to the central, having also one, perhaps more rows 

 behind, which are shorter. 



The predominant hue of this fish is a tawny or fawn colour ; 

 the opercula silvery; head metallic gray; muzzle blackish, 

 slightly projecting. 



There are six rows of rather quadrangular black spots, more 

 particularly marked in the posterior half of the body, averaging 

 twenty-five spots for each row. These black spots, resting on a 

 tawny ground, leaving intervals something larger than them- 

 selves, give a picturesque appearance, forming stripes of alter- 

 nating hues, the three upper of which slightly curve corresponding 

 to the arching back ; but each succeeding one becomes straighter, 

 the fourth and fifth being nearly straight ; the sixth, or lov/er row, 

 follows the abdominal curve, and disappears at the anal fin ; the 

 other five rows gradually converge without coalescing at the 

 origin of the caudal fin. At the origin of this fin the spots are 

 displaced out of line. By this arrangement the six rows of 

 alternating black and tawny leave in the longitudinal direction 

 six other continuous tawny stripes, all of which except the two 

 interrupted ones, lost at the anal fin, converge without mingling 

 in the tail, all being about equal in length. The colours fade 



