DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
559 
As to time, the larvae are distributed over the entire summer, appearing first in 
May and a few stragglers as late as December, but they were common to abundant 
only from June to September. 
GROWTH 
Growth in Gobiosoma probably progresses moderately fast. It is not always 
an easy matter, however, to distinguish between those of the 0-class and the older 
ones, as the sizes intergrade during late summer. Specimens 18 mm long, taken in 
August, are recognizable as young of the current season and may be among the largest 
of their year class. Larger examples of the current year, if present, apparently 
could not be recognized, for they are as fully developed as the adults. Since the spawn- 
ing season may be said to end, except for an occasional late spawner, by the end of 
August, it seems unlikely that the largest young become mature during their first 
summer. However, sexual maturity is reached at a very small size, for we have seen 
a few gravid females only 23 mm long and many gravid ones from 25 to 30 mm in 
length. Therefore, the authors are not prepared to state positively that none of the 
young become mature during their first summer, but they regard it as quite unlikely. 
It seems highly probable, however, that sexual maturity is reached during their 
second summer. 
MICROGOBIUS HOLMESI SMITH. HOLMES GOBY 
Two very closely related species of Microgobius, namely eulepis and holmesi, 
are recognized from North Carolina. As understood by us eulepis has a somewhat 
more slender and less strongly compressed body than holmesi, the depth in the former 
in the two specimens at hand is contained respectively 6.5 and 7.0 in the standard 
length, whereas in eight specimens of the latter the depth goes into the length 4.7 
to 5.75 times. The mouth in eulepis appears to be rather more nearly vertical and 
the ventral disk is shorter, failing to reach the vent, whereas in holmesi the disk 
usually reaches to or beyond the vent. It is possible that holmesi may grow some- 
what larger. However, it seems probable that a further study based on a larger 
number of specimens than is now available may show that the two nominal species 
intergrade, and in fact are identical. As now understood eulepis is very rare at 
Beaufort, whereas holmesi is moderately common. The known range of the two 
species is coterminous extending from Chesapeake Bay to North Carolina. 5 
The sexes are readily separable in M. holmesi, as the male has a row of prominent 
black spots on the interradial membranes of the anal just below the pale margin of 
the fin. These spots are entirely missing in the female, in which, as contrasted to 
the male, the membranes between the longest dorsal spines is jet black distally. In 
general, the males also have higher fins. The ventral disk, for example, usually 
reaches the origin of the anal in adult males, whereas it frequently reaches only to 
the vent in adult females. Furthermore, the females, at least during the breeding 
season, have a larger anal papilla. Whether similar sexual differences exist in eulepis 
cannot be stated at this time. The two specimens in the present collection in general 
agree in color with the females of holmesi . 6 
It is not surprising that the larval and young Microgobius do not appear to be 
separable into two species (if indeed more than one species is represented) since the 
adults of the local representatives are very closely related. Since M. holmesi is com- 
» Since the preparation of this manuscript Isaac Ginsburg, who has made a special study of the American gobies, concluded 
(Copeia, No. 1, 1934, p. 35) that M. holmesi and M. eulepis are identical and that both are synonyms of M. thalassinus. 
• Smith (1907, p. 367) presents a very satisfactory illustration of an adult male Microgobius holmesi. 
