399 Part III —Highteenth Annual Report 
from the end of the furca and one from a notch on the outer margin ; 
the small hair is also marginal. 
The male and female have each three abdominal segments. Those of 
the male are nearly of equal size, but in the female the genital segment 
is about as long as the combined length of the next two, and it is 
provided on the ventral aspect with two moderately long sete. In the 
specimen figured (fig. 15) several minute ova were observed attached to 
these genital setze, as shown in the drawing. The fifth thoracic feet in 
the female (fig. 18) are sub-cylindrical, and rather longer than broad, 
and carry two apical sete. 
Monstrilia dane appears to be more frequent in Upper Loch Fyne 
than in the seaward part of the Clyde. In a tow-net gathering collected 
on the 28th November last (1899) near the head of the loch as many as 
twenty-seven specimens of Monstrilla were obtained, apparently all 
belonging to this species. Buta much larger number of specimens was 
obtained in a gathering collected, also near the head of the loch, in the 
month of September immediately preceding. This gathering, which was 
collected with the surface tow-net on the 29th of the month referred to, 
was a small gathering, and contained a considerable quantity of fibrous 
matter. It was not examined until the following month of March, when 
over eighty specimens were obtained! The specimens comprised both 
males and females, but whether they all belong to the one species I am 
not yet in a position to say. The fact that such a large number of 
specimens was found in a single small gathering is of no little interest in 
its bearing on the distribution of these curious animals. 
Pseudanthessius thorellii (Brady and Robertson). 
1875. Lichomolgus thorellit, B. and R., Brit. Assoc. Report, 
OES Th 
This species, which is one of the. Lichomolgide distinguished by the 
possession of elongated caudal iurca, has been obtained in dredged 
material from various parts of the Clyde area. It is quite easily dis- 
tinguished from Lichomolgus forficula, which also has long furca, not 
only by the structure of the inner branches of the fourth pair of 
swimming-feet and the difference in the proportional lengths of the 
abdominal segments, but also by the difference in habitat. Lichomolgus 
forficula lives in the branchial cavity of large Ascidians, while 
Pseudanthessius thoreilii appears to live free amongst weed or zoophytes, 
and perhaps also amongst /ilograna. I have not on any occasion found 
it naturally inside an Ascidian, and neither does Professor Brady in his 
description of the species refer to it as a commensal. 
Hermanella arenicola (G. S. Brady). 
1872.  Boeckia arenicola, G. 8S. Brady, Nat. Hist. Trans., 
Northumberland and Durham, vol. iv., p. 430. 
A specimen of this fine species was obtained in a gathering of entomo: 
straca from Loch Gilp (near Ardrishaig, Loch Fyne), which is a new 
Clyde Station for this species. The vicinity of Otter Spit is the only 
other locality within the Clyde area that I know of where Hermanella 
arenicola has been obtained. 
Asterocheres (1) echinicola (Norman). (Pl. XIV., figs.33~36.) 
An Asterocheres is obtained in the water passages of a sponge (Suberites 
sp.), common both in the Clyde and Loch Iyne, which is closely allied to 
Asterocheres echinicola (Norman), aud which may probably be only a 
