304 Part III. — Ninth Annual Report 



Porcellidium fimbriatum, Claus. 



1863. Porcellidium fimbriatum, Claus., ' Die frei lebenden Cope- 



poden,' p. 140, t. xxii. fig. 1. 

 1880. Porcellidum fimbriatum, Brady, loc. cit., vol. ii. p. 167, pi. 

 lxx. 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 fur cillatus, Thorell. 



1859. Lichomolgus furcillatus, Thorell, ' Om Krustaceer i Ascedier,' 



p. 74, t. xiii. fig. 20. 

 1880. Lichomolgus furcillatus, Brady, loc. cit, vol. iii. p. 49, pi. 

 lxxxviii. 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 c 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. 



CoRYOEnm 



Monstrilla rigida (J. C. Thompson), $ . 



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 ser.), p. 565, pi. xxxvii. figs. 8, 



11-12. 



Habitat. — Off Musselburgh, in bottom tow-net. A specimen, apparently 

 belonging to this species, was obtained 25th March this year (1891).t It 

 has three setse 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^;. 

 Caligus 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 

 Monstrilla ; though the mouth is quite distinct, there is little, if any, trace of an 

 alimentary track, but there surely must be such a track, however indistinct. 



