DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
619 
in development. The pectoral fin membranes remain short and broad, and without 
definite rays. The ventral hairlike rays (apparently three in number) have increased 
in length and reach well beyond the vent, the fins remaining inserted laterally below 
the base of the pectorals. 
Black chromatophores remain present on the upper surface of the head, on the 
back below the anterior half to two-thirds of the dorsal, and occasionally one or more 
black dots are present at the base of anal. A dark lateral stripe, variable in length, 
is generally situated above the anterior half of the anal. A dusky area extends 
upward and forward from the vent, and often a dusky area is present at the upper 
angle of the gill opening, sometimes extending downward just posterior to the opercle. 
The fins remain without color, the ventrals being pale throughout. 
U. chuss seems to differ from U. regius principally in the rather more slender 
body and in having a proportionately longer and more slender tail, the depth of the 
body being contained 3.5 times in the length to the end of the notochord; and the 
tail, from the vent to the tip of the notochord, is contained 2.2 times in the length. 
The depth just posterior to the vent is contained 2.3 times in the length of the caudal 
portion of the body to the tip of the notochord. In color U. clmss differs principally 
in that the interradial membranes of the ventrals are black distally (fig. 131). 
Figtjee 131. — Urophycis chuss. From a specimen 5 mm long. 
Specimens about 7.0 mm long . — The most important advancement is the develop- 
ment of rays, or at least the fulcra, of most of the dorsal, and to a somewhat lesser 
extent of the anal rays. The number of rays in the second dorsal, as pointed out else- 
where, is diagnostic, as thereby regius (with 46 to 51 rays) is distinguished from the 
other local species, which have a greater number of rays. It is possible now, with 
transmitted light and fairly high magnification, to count about 43 fulcra in the second 
dorsal and about 45 in the anal in specimens with deep short tails, winch have no black 
on the ventral fins. The specimens with short deep tails and without black on the 
ventrals among the younger stages, as indicated, were suspected of being regius. At 
a length of about 7.0 mm they may be so designated quite definitely, as shown 
subsequently. 
The specimens with the rather longer and more slender tails, and with the ventrals 
distally black have about 50 to 52 fulcra developed in the second dorsal. The anal 
is somewhat more retarded in development than the dorsal and the rays and fulcra 
are not nearly all developed. Although the dorsal fulcra evidently, too, are not quite 
all developed, it is evident that the number that will be developed is greater than in 
adult regius. The specimens with the higher number of fulcra, developed at a length 
of about 7.0 mm, are from the vicinity of Cape Henry, Va., farther north than flori- 
danus is known to occur. The only species recorded from the coast of Virginia are 
