EEPORT Olf THE TE^HICATA. 
131 
Distaplia magnilarva. In some specimens of Distaplia rosea from the Bay of Naples, which 
I have examined, the musculature is less marked and less regular than in the new species. 
The branchial sac is remarkable on account of the large size of the stiomata 
O O 
(PL XVIII. fig. 6, sg.). They are long and narrow like those of Colella pedunculata, 
and are arranged with great regularity. Each row is crossed about the middle by 
a narrow transverse vessel or horizontal membrane (PI. XVIII. fig. 6, tv') which does 
not interrupt the stigmata, and is considerably thinner than the regular transverse 
vessel betw^een the rows. In a specimen of Distaplia rosea from Naples,^ which I have 
examined, the branchial sac shows precisely the structure which I find in the Challenger 
species (compare PI. XVIII. figs. 3 and 6), and difiers considerably from the figure given by 
Della Valle.^ The latter shows, in the branchial sac, each row consisting of five short 
stigmata, all of the same size, and not crossed by any horizontal m.embrane ; while I find 
in all the Ascidiozooids which I have examined of the Naples specimen of Distaplia 
rosea, that there are from twenty to thirty long stigmata in each of the four rows, that 
those in the middle of the row are the longest, the size decreasing towards each end, and 
especially towards the ventral end (see PI. XVIII. fig. 3), and that each row is crossed by 
a distinct horizontal membrane. The rapid decrease in size of the stigmata as they 
approach the ventral end of the row allows the transverse vessels to enlarge rapidly into 
triangular areas wdiich abut against the sides of the endostyle (PI. XVIII. fig. 3, tr.). 
In other respects the Naples specimen of Distaplia rosea agrees w^ell with Della Valle’s 
description and figures of that species. 
The dorsal languets are short, triangular, and pointed, and, like those of Distaplia 
rosea, they are not quite in the median dorsal line but slightly to one side. Della Valle 
states that there are no languets in Distaplia magnilarva. 
The tentacles of Distaplia vallii are rather irregular in size. There are eight 
rather larger and some intermediate smaller and more irregularly placed ones. The 
larger tentacles are pigmented. 
The alimentary canal is like that of Distaplia magnilarva in all essential characters. 
It is pigmented with opaque white, red, and black patches. The vascular ectodermal 
appendages are long. 
The reproductive organs are hermaphrodite and of large size. They usually 
consist of one or two large opaque yellow ova and a number of ovate or sausage-shaped 
testes of a dull brick-red colour. The vas deferens is conspicuous, and is also coloured red. 
The tailed larvae are about 1 mm. in greatest length. They are thus about half the 
size of those of Distaplia magnilarva according to Della Valle. The body is ovate, with 
the usual three adhering processes in front. The larval tail is short. 
On the whole Distaplia vallii is closely related to Distaplia magnilarva and to 
1 Obtained named from the Zoological Station, Naples. 
^ Nuove Contribuzioni, &c., Tav. i. fig. 9. 
