MUSEUM OF COMPARATIVE ZOOLOGY. 81 
distribution of the papille of Typhlogobius are shown, except for a few 
scattering ones to be spoken of shortly, in Plate I. Figure 3, pap. 
There are two series near the edge of each side of the lower jaw, 
running parallel with it. The series of one side do not quite unite, 
anteriorly, with those of the opposite side, the interval between their 
ends being occupied by a slight prominence in the epidermis. Posteriorly 
the series extend beyond the angle of the mouth and turn upward some- 
what to terminate about on a level with the mouth opening; the rows 
nearer the median line, however, extending slightly farther than the 
ones nearer the edges of the jaws (Fig. 3). The papille of the inner 
series are considerably larger than those of the outer series, there 
being about six of the former to thirteen of the latter. The larger 
ones are on the average about 0.08 mm. in diameter, though the size 
varies considerably. The papillze of the outer series are situated on a 
quite prominent ridge, while the inner ones are, on the contrary, in a 
shallow furrow. These ridges and furrows are, however, apparently 
a part of the longitudinal foldings in the integument that are charac- 
teristic of this region of the head, rather than structures expressly for 
the accommodation of the sense buds. Another series of papille is 
found on each side of the head above the mouth, and having very 
nearly the same direction as those below, though inclining toward 
the latter somewhat in their course backward. These extend anteri- 
orly to near the tips of the fleshy knobs shown at f, Figure 1. The 
papillee above the mouth are of about the same size as the smaller ones 
on the lower jaw. Still another series is found on each side of the 
head on the operculum, extending however at a right angle, or nearly 
so, to the series already described (Fig. 3). These are also of the 
smaller variety. The number in both this and the upper-jaw series is 
more variable that in the lower-jaw series, though the transverse series 
never extend far on to the top of the head. 
In Lepidogobius and Clevelandia both lower-jaw series are present, 
and have precisely the same arrangement and form as in Typhlogobius ; 
and in addition papillae are numerously present on various parts of 
the head and body where they do not occur in Typhlogobius. Thus 
on the head of Lepidogobius there are at least several hundred in addi- 
tion to the ones on the lower jaw. On each side of the head, beginning 
at a point a little above the mouth and somewhat nearer its angle 
than the end of the snout, four rows take their origin and diverge 
irregularly. The row nearest the mouth bends downward somewhat as, 
in its backward course, it reaches the angle of the mouth, and it extends, 
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