minute conical teeth on its concave edge. 
NATURAL HISTORY OF PALOLO, OR MBALOLO. 239 
=- 
The bundles of sete generally consist of two 
or three of each of these forms, the latter holding a position inferior to the former. 
Mbalolo has been supposed to exhibit an alliance with Arenicola; but the anatomical 
characters above given refer it, very clearly, to the Nereide. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
= 0. 
QD 
DESCRIPTION OF THE PLATE. 
Tas. XLI. 
. Portion of Mbalolo. Natural size. | 
. Magnified figure of the head, with its three frontal tentacula and eyes, each of which appears to 
consist of two distinct organs closely approximated. The position of the retracted jaws is 
shown in the central dark space behind the tentacula. , 
. The double set of jaws, with their basal plates. 
- The palatal ? erectile plates noticed in the text. 
. Three of the feet, seen from below: a. setigerous tubercle; 5, b, b. dorsal cirri; c, c, c. ventral 
cirri; d. muscles which protrude the aciculi, acting through the basal stylet, e; f. retractor 
muscles, derived from the lateral border of a longitudinal muscular band, 9, running along the 
ventral surface. 
. Posterior extremity of the Mbalolo, dorsal aspect: a. terminal dorsal cirri; 5. terminal ventral 
cirri, or oval styles so called. 
- Basal stylet, or that which affords support to the lateral tubercles. 
. Whip-like aciculus. 
. Clawed aciculus. 
