329 
In its internal structure the species very much approaches Acasta, 
and is indeed only to be distinguished from this genus by its fixed 
basis. 
The labrum has three denticles at each side of the deep notch. 
The man di ble has three main teeth, and at the lower angle three 
small teeth. The blade has a narrow belt of rather long hairs along 
the cutting edge. 
The maxi 11a has at its upper margin two large spines, and 
below these an indication of a notch; the following five spines of 
the cutting edge are a little 
smaller than the upper two, 
and below the five spines 
there is one long spine, as 
long as, or even a little 
longer than the upper two; 
below this long spine a 
somewhat smaller one, and 
at the lower angle two 
quite small and delicate 
spines are placed. The blade 
hasonly longerdelicate hairs 
just inside the cutting edge. 
Among the cirri only the shorter ramus of cirrus IV has 
small spinelike denticles on the anterior side of the basal and 
median segments; there are three or seldom four denticles present 
in the segment. Neither denticles nor hooks are found in cirrus III. 
Cirrus I has rami with 5 and 11 segments; the shorter ramus 
is half as long as the longer one. In cirrus II the shorter ramus 
measures of the longer one; the numbers of segments are 5 
and 7. Cirrus III has subequal rami with 7 and 8 segments. 
Also in cirrus IV the rami are subequal, and have 14 and 17 
segments; only in the shorter ramus the basal and median segments 
are armed with small denticles besides the long spines. The post- 
erior cirri have three or exceptionally four pairs of anterior spines 
Fig. 66. Balanus dentifer from 32° 15’ N., 128 8 
12 ’ E. a labrum, b mandible, c maxilla, d 
fourth segment of cirrus IV. [a—c X 44, 
d X 66], 
on the segments. 
The penis is extraordinarily long, more than twice as long as 
the entire body of the animal including the cirri. It is annulated 
all over, its distal part furnished with scattered, long hairs. 
