304 
Fart III. — Ninth Annual Report 
PorcelUdium fimbriatum, Claus. 
1863. PorcelUdium Ji7nbriat um, CIslms., ' Die f rei lebenden Cope- 
podeii,' p. 140, t. xxii. fig. 1. 
1880. Porcellidum fimbriatum^ Brady, loc. cit, vol. ii. p. 167, pi. 
Ixx. figs. 1-4. 
Habitat. — Largo Bay, among weed brought up by the dredged ; a few 
specimens only were obtained. The caudal segments of the Forth specimens 
have four small setae at the outer and one at the inner angles ; the outer 
margins of the last thoracic segments have a deep notch nearly midway 
between their extremities and the extremities of the preceding segment, 
and a stout ciliated tooth projects from the upper edge of the notch ; 
the last thoracic segment has its outer margins also much more strongly 
ciliated than the margins of any of the preceding segments. 
Lichomolgus furcillatus^ Thorell. 
1859. Ldchomohius furcillatus, Thorell, ' Om Krustaceer i Ascedier,' 
p. 74, t. xiii. fig. 20. 
1880. Lichomolgus furcillatus, Brady, loc. cit., vol. iii. p. 49, pi. 
Ixxxviii. figs. 10-14. 
Habitat. — In branchial sac of an Ascidian, brought up in the trawl-net 
west of May Island, 31st April 1890 ; one specimen."^ The anterior 
antennae of this species are six-jointed, which thus differs from L. fucicolus 
Moreover, this last appears to be ' an entirely free-living ' species. 
Another species, L. forficula, that I have frequently obtained in large 
Ascidians in East Loch Tarbert, Loch Fyne, and in Scapa Flow, Orkney, 
has not yet been observed in the Forth. 
CoRYCiEIDiE. 
Monstrilla rigida (J. C. Thompson), 9 • 
1 887. Cymbasoma rigida, J. C. Thompson, ' Jour. Linn. Soc. 
(Zool.),' vol. XX.. p. 154, pi. xiii. figs. 1-4. 
1890. Monstrilla rigida, Bourne, 'Quart, Jour. Microscopical 
Science,' vol. xxx. (new sen), p. 565, pi. xxxvii. figs. 8, 
11-12. 
Habitat. — OfiP Musselburgh, in bottom tow-net. A specimen, apparently 
belonging to this species, was obtained 25th March this year (1891). f It 
has three setae to each of the caudal furca, the penultimate abdominal 
segment is considerably longer and stouter than the last one, and furnished 
with a genital appendage. The genital appendage (setae) is very little 
longer than the furcal setae. Several other specimens belonging to this 
interesting genus have been obtained in the Firth of Forth and in St 
Andrews Bay during the past year, but I have not yet had time to 
examine them. 
PARASITA. 
Caligid^. 
Ccdigus diaphanus, Nordmann. 
1832. Caligus diaphanus, Nordmann, ' Microgr. Beitr.,' ii. p. 26. 
1850. Caligus diaphanus, Baird, 'Brit. Entom.,' p. 269, pi. xxxii. 
fig. 1. 
* I have recently obtained a few more specimens east of Inchkeith in Ascidians. 
t J. C. Thompson, F.L.S. , F.R.M.S., Liverpool, to whom I sent the specimen, 
confirms my diagnosis. Little or nothing is yet known of the internal structure of 
Mo7istrilla ; though the mouth is quite distinct, thei'e is little, if any, trace of an 
alimentary track, but there surely must be such a track, however indistinct. 
