KEPORT ON THE ANNELIDA. 
245 
are short, broad, and pointed. Each great dental plate has four teeth. Three lateral 
plates occur in front of the latter, viz., a somewhat elongated plate next the foregoing, 
terminating in a sharp tooth ; a quadrangular plate immediately in front (in ordinary 
positions), with a minute tooth at its upper and inner edge ; and a triangular plate (like 
a cocked hat) fitting into the space formed on the outer side of the other two. An 
accessory plate lies outside the last, and a small bar occurs some distance in front of the 
long horny crescentic process running backward by the side of the maxillae. The chief 
plates of the dental apparatus are of a brownish colour. In the mandibles (Fig. 11) 
the ventral dentary surface is crescentic, the external edge being pointed, and the whole 
marked by parallel veins. The anterior edge has a slightly tuberculated whitish 
deposit. The limbs are united backward to the terminal third. 
At first sight the feet do not appear to differ much from those of Lumbriconereis 
fragilis, except in the shorter bristles, but a closer inspection shows (PI. XXVI. figs. 14, 
15) that the posterior elongated lobe is pointed superiorly in the Japanese form. The 
bristles are arranged in four groups, one of which, the inferior, is compound. The two 
superior fasciculi are composed of the ordinary bristles, with slightly brownish shafts and 
winged tips. The third series consists of about five jointed hooks (PI. XVIIa. fig. 17) with 
a very narrow wing along the ventral edge. The serrations on the crown of the 
hook are obscure, and are either abraded or originally defective. 
The posterior hooks (PI. XVIIIa. fig. 1) have longer and more slender tips than in 
the British form above mentioned, and, like the anterior, their crowns are smaller. A 
series of small teeth occurs, as usual, above the larger process interiorly, and a distinct 
incurvation of the wing exists just below the crown. 
In comparing this form with the British Lumbriconereis joJinstoni, the dorsal winged 
bristles are longer and more attenuate, as are also the jointed hooks, the crowns of the 
latter, moreover, being less distinctly serrated. The bristles are more numerous in the 
Japanese species, and the posterior lamellae more acute superiorly. The spines in the 
foreign forms are black, whereas in the British they are pale. 
The intestine contains brownish mud, in which Diatoms, fragments of Crustacea, 
minute bristles of Polynoe, sponge-spicules, and peculiar ova are present. 
In section the ventral nerve-cords have a much broader and shorter pedicle than in 
the common Lumbriconereis, and the neural canal is somewhat less. The central fibrous 
bundle of each nerve-cord is well seen in some sections just below the canal. The 
oblique muscles have the normal attachment superiorly. Some fibres of the circular 
muscular coat cross the nerve-area. 
In the structure of the feet this form closely approaches Marenzeller’s Lumbriconereis 
japoniea,^ from Southern Japan. There is a little discrepancy, however, in the outlines 
of the soft parts, and still more in the minute structure of the hooks, both anterior and 
^ Sildjapan. Annel., p. 29, Taf. v. fig. 3. 
