598 
BULLETIN OF THE BUREAU OF FISHERIES 
Blennies of this size are difficult to identify. However, the specimens assigned to 
this species are a little less robust than those referred to Hypsoblennius hentz. Further- 
more, those of the last-mentioned species have rather larger pectoral fin membranes 
with the basal two-thirds or three-fourths spotted with black, whereas specimens of H. 
geminatus have black only on the fleshy base of that fin. 
It will be seen from the two foregoing descriptions that the live fish at hatching 
are longer than the larvae just described, although the latter are somewhat more 
advanced in development. The difference, no doubt, is the result of shrinkage during 
preservation in the last-mentioned group. 
Specimens 2.0 to 3.0 mm long. — The body is rather strongly compressed through- 
out, the head being about half as broad as deep. The head and trunk are short in 
proportion to the tail, the distance from the tip of the snout to the vent being con- 
tained about 2.9 times in the total length without the caudal finfold. The snout, 
although rather blunt, especially in 2.0-mm fish, is more pointed than in Hypsoblennius 
hentz and about one-third (in 2.0-mm fish) to two-thirds (in 3.0-mm fish) the length of 
the eye. The mouth is terminal and strongly oblique, with the tip of the lower jaw a 
little above the level of the middle of the eye when the mouth is closed. The vertical 
finfold is continuous with indications of rays posteriorly in 3.0-mm fish, but not in 
smaller ones. The pectoral fins are short and broad and scarcely longer than the eye. 
A broad black oblique band extends from the axile of the pectoral to ventral outline 
just above the protruding hindgut. The ventral outline of the chest and abdomen 
usually bear a few dark dots, the upper surface of the head and nape generally has one 
or more dark cliromatophores, and usually a faint dark bar across the forehead between 
the eyes. A row of small, vertical, slightly elongate dark spots is situated on the 
ventral outline of the tail. Dark dots also are present on the base of the inner surface 
of the short pectorals (fig. 104). 
This species is distinguished from Hypsoblennius hentz at this size chiefly by the 
longer and more pointed snout, less strongly elevated forehead, the more strongly 
oblique mouth, and the much shorter and broader pectorals which bear dark dots 
only at the base on the inner surface, whereas in H. hentz the dark specks extend to 
the tips of the fins. These differences are evident in specimens as small as 2.0 mm in 
length. Smaller larvae, as already stated, are difficult to identify. 
Specimens J+.O to 4-5 mm long.— The head and body are compressed, the caudal 
portion of the body being longer than the head and trunk, with the vent situated well 
in advance of midbody length. The head is deep and rather narrow, the interorbital 
space being only about half the width of eye. The snout is moderately pointed and 
about three-fourths as long as eye. The mouth is terminal, rather strongly oblique, 
the tip of the lower jaw being scarcely below the level of the middle of the eye. The 
eye is placed moderately high and is about equidistant from the dorsal and ventral 
