Nowt|), az DEVELOPMENT OF BALANOGLOSSUS. 25 
Tornaria of this sort, but it cannot be found in the series of 
preserved forms. 
In general, the structure of the Tornaria is like the larger 
form shown in Fig. 3, Pl. I. Both were drawn to the same 
scale. The larger form I have spoken of as the Bahama 
Tornaria, and I take the liberty of christening the smaller 
form the Bimini Tornaria. 
The course followed by the anterior ciliated band differs 
from the Bahama Tornaria in these respects: The lower hori- 
zontal limb of the anterior band does not turn forward at the 
middle of the side of the larva, but continues toward the dorsal 
surface. Before reaching the mid-dorsal line it turns back 
again (on each side) to follow a parallel line as far as the 
middle of the side of the larva. Then it turns forward along 
the middle lateral area. The course of the band after this 
follows the path characteristic for Tornaria. 
The second peculiarity of the band is that it is drawn out 
into a few tentacle-like processes. These tentacles are neither 
so long nor so numerous as in the Bahama form. In this 
respect the Bimini form stands midway between the New Eng- 
land Tornaria without tentacles and the Bahama form with its 
large fringe of tentacles. 
The third peculiarity relates to the apical plate. T'wo semi- 
circular eye-specks are found at the apex of the larva. The 
ciliated bands converge towards these, but the bands do not 
run parallel in two pairs one on each side as in the larger 
Tornaria, but sweep around and disappear in the region of 
the eyes, as in the very young larvae of the Bahama form. 
The apical plate of the larva was pulled in slightly and I could 
not determine the method of ending of the bands. When 
looked at from above the anterior portion of the bands are seen 
to approach much more nearly to one another from side to side 
than in the Bahama form. 
The digestive tract with its three divisions is seen in the 
interior of the larva. On the walls of the digestive tract, where 
the stomach joins the intestine two oval bodies are distinctly 
seen on each side (on only one side of figure). These represent 
the second and third pairs of body-cavities that are formed in 
