THE ARMED BULL-HEAD FAMILY. 145 



It is thus difficult to extrude a perfect embryo. Under a 

 low power the torn edge shows layer upon layer of the 

 secretion. 



The larva immediately after hatching closely corresponds 

 with that captured in the bay, and figured by Prof. Prince 

 {Researches, Plate XVIII, fig. 11). The body is about 7 mm. 

 long, the tail, which has embryonic fin-rays, being somewhat 

 longer than in the sketch. The head has large silvery eyes, 

 with greenish-yellow pigment behind them, and around and 

 below the widely-open mouth. The snout is blunt, and the 

 ear-capsules large. The trunk, generally, is dotted over with 

 the same greenish-yellow pigment (ochreous by transmitted 

 light), which is also present in streaks on the basal region of 

 the breast-fins, on the yolk-sac, and on the prominent cone at 

 the vent. The three dorsal patches in the marginal fin are 

 distinctly separated, the first being small, and nearly in a line 

 running upward from the posterior border of the vent; the 

 second about the widest part of the fin, and the third about the 

 posterior region of the same dilatation. In numerous examples 

 obtained in the tow-net in March the three yellow dorsal 

 patches had opaque-white tips, thus giving them a striking 

 aspect. Opposite the two latter is a corresponding patch 

 ventrally. A similar touch of yellow occurs at the commence- 

 ment of the tail. Numerous stellate black pigment-spots are 

 present on the yolk-sac, a few on the breast-fin, and a series 

 along the dorsal and ventral margins of the body as far as the 

 third patch of yellow on the marginal fin. One or two occur 

 on the border of the marginal fin, and a considerable number 

 in the ventral patch of yellow (second) in the latter, while only 

 a very few are found in the dorsal patch opposite it. Two 

 exist in the ventral touch behind the former and only traces in 

 the dorsal patch opposite. One or two chromatophores also 

 occur ventrally in the patch at the root of the tail. The black 

 pigment would seem to be better developed ventrally than 

 dorsally. 



The larval examples appear in the various nets in the 

 beginning of April, and measure 7 to 8 mm. in length. They 

 soon become abundant, especially in the bottom-nets, their 

 M. P, 10 



