Gatty Marine Laboratory, St. Andrews. 129 
two slender subulate tentacular cirri, which are nearer each 
other than the corresponding organs in Eunice. In contrast 
with the Neapolitan examples, the specimen procured by the 
‘ Porcupine’ is much smaller, its tentacles rather longer, 
the branchial spirals have shorter pinne, and its coloration 
less deep. 
The dental apparatus in examples of Diopatra neapolitana 
from Naples and that from the ‘ Porcupine’ is very closely 
allied. In both the colour is pale chocolate, with a dark 
brown bar separating the maxillz from the posterior appen- 
dages, a dark brown spot at the posterior end of each great 
dental plate, and a narrow, slightly fusiform, brown belt 
bounding the curved anterior plates and appearing on the 
ventral surface. The curvature of the maxille is the same 
in both, and the tips, which leave the horizontal plane, are 
more deeply tinted than the rest. The posterior appendages 
form together a spatula-shaped structure with a notch 
between them posteriorly, and a constriction where they 
join the maxillary suture. In proportion to its size the 
spathulate enlargements of these processes are shorter and 
broader in the Neapolitan form, and a distinct flange a 
short distance from the inner edge just in front of the 
articulation with the posterior appendages is present on 
each maxilla. The small size of the example from the 
‘ Porcupine” may, however, account for the indistinctness 
of such a structure. The left great dental plate in the 
Neapolitan has eight teeth ; in the ‘ Porcupine’ form there 
are ten. The azygos plate in the former has six teeth—a 
portion posteriorly having a smooth edge; in the latter 
seven or eight. The right great dental plate in the former 
has seven teeth, and, like the plate of the opposite side, an 
additional slight elevation ; in the latter this plate has seven 
teetn, an adjoining elevation, and a longer bare margin 
posteriorly. The left anterior curved plate has five teeth in 
the Neapolitan; in the other apparently the same number. 
The former has a horny plate externally, with a single tooth 
and a small plate behind; the latter also shows a horny 
point on a small plate, but the specimen is incomplete. In 
the former the right anterior curved plate has eight teeth, 
and the outer plate a single tooth; in the latter the right 
anterior curved plate has at least seven teeth, and an outer 
plate with a horny tooth. 
The dentary edge of the mandibles in the Neapolitan form 
shows a larger foliate outer tooth, a middle stout conical 
tooth, and an inner rounded ridge. A dark brown touch 
Ann. & Mag. N. Hist. Ser. 7. Vol. xii. 9 
