340 THE DOLABELLINAE. - 
3.0 mm. broad, while the apparent external dimensions reach a length of 3.0 
mm. and a breadth of fully 5.5 mm. The ganglia are closely united by a very 
short and broad buccal commissure. 
Buccal nerves.—From the buccal ganglia are given off three paired nerves _ 
and a single unpaired median one. 
The anterior unpaired nerve (Plate 3, fig. 3, b/.) is completely concealed — 
from view by the capsule. Though apparently a single unpaired nerve, it 
actually arises by a root from each ganglion, close in front of the commissure 
upon the dorsal surface. These separate roots at once fuse into a single median 
trunk which almost immediately bifurcates into two equal rami, that pass upward 
into the ventral wall of the bulb. Each gives off several delicate branches to — 
the superficial wall-muscles, and then penetrates upward and outward to the 
rotella, to which each is distributed in a number of branches. Upon the dorsal — 
surface of the first nerve, immediately before its bifurcation, a pair of very 
delicate branches, 6 /a, are given off, which are distributed to the superficial — 
muscles of the floor of the bulb immediately in front of the buccal ganglion. — 
These are also shown in dorsal view in Plate 3, fig. 4, Ja. : 
The paired nerves from the buccal ganglia in Dolabella agassizi appear 
upon their exit from the capsule as six independent nerves, corresponding to 
the number given by Amaudrut (1886). This is at some distance from the 
actual ganglia however, and in a cleared preparation the real origin of these 
nerves may be traced back to the ganglia proper, and the apparent number 
becomes reduced to but three main nerve-trunks upon each side. These 
nerves are numbered in sequence in Plate 3, fig. 3 as b 2, b 3, and b 4, b1 being 
the single median trunk just described. . 
The second buccal nerve, b 2, arises from the outer lateral margin of either 
ganglion. It bifurecates at a short distance, giving rise to a posterior ramus, — 
c-b, con, which courses around the bulb dorsally and unites with the cerebral 
ganglia, forming the cerebro-buccal connective (Plate 2, c-b. con.). The anterior 3 
ramus of the second buccal nerve divides at once into two branches, 2¢ and 2d. 
The branch 2d enters the large protractor bulbi muscle at its insertion into 
the pharyngeal bulb and gives off a number of fine branches to it, the main — 
nerve passing on forward into the ventro-lateral muscles of the anterior portion 
of the bulb itself, a slender branch being continued forward and distributed 
to the anterior ventral protractor muscles of the bulb at their insertion into 
the latter. The branch 2c passes obliquely forward and upward to the lateral — 
wall, above the insertion of the lateral protractor bulbi muscle, giving off several 
