DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
557 
from the presence of two scales on the base of the caudal fin, previously described 
(p. 548), which bosci does not possess (fig. 47). 
The development of adult characters at a larger size in ginsburgi than in bosci sug- 
gests that the first-mentioned species might reach a larger size. Judging from the 
adults taken this is not the case, for on the contrary the largest specimens in the 
collection are bosci. 
Specimens 15 mm long . — At this size bosci is robust anteriorly, the depth being 
contained about 5.3 times in the length to base of caudal fin; the head is depressed 
and quite as broad as deep; the snout is blunt; the eyes are directed slightly upward; 
the mouth is small, gently oblique, and terminal to slightly inferior; the maxillary 
reaches a little past anterior margin of eye; the fins are all fully developed, the margin 
of the caudal fin now being slightly rounded; and the body is fully pigmented. It is 
evident, therefore, that fish of this size have acquired nearly all the characters of the 
adult and are readily identifiable with the grown fish (fig. 48). 
Figure 48 .—Gobiosoma bosci. From a specimen 15 mm long. 
It is possible to identify the young at a length of about 15 mm as to species with 
a reasonable degree of certainty. G. ginsburgi, at this size, is notably more slender, the 
depth being contained in the total length about 6.1 times. The greater length of the 
ventral disk, winch (having attained its highest state of development at about this 
