of the Fishery Board for Scotland. 291 



Fam. CALiGiDiE. 

 Genus Caligus, Miiller (1785). 



Galigus lahmcis, T. S., sp. nov. PI. XIII., fig. 2G-29 



Description of the Female. — Length about 3'3 mm. (about ^ of an inch). 

 The cephalic shield (fig. 26) is about as broad as long; it is widest 

 near the posterior end, and has the margins evenly rounded, somewhat 

 like Calig^is diaphanus, Nordmann. The last thoracic segment is sub- 

 quadrate in outline, but its length is only equal to about three-fourths of 

 the breadth ; it is considerably smaller than the cephalic segment, being 

 little more than a third of the length of that segment and half its breadth. 

 The abdomen (exclusive of the caudal furca) is equal to about half the 

 length of the last thoracic segment, and is apparently unsegmented, as 

 shown in the figure. 



The fourth pair of thoracic feet are small, and the single branch in each 

 is composed of two joints, which are armed with sabre-like spines 

 (fig. 29). 



The sternal fork (fig. 28) is stout ; both branches are moderately 

 bi'oad, and obliquely truncate at the ends, and are not greatly divergent. 



The male (fig. 27) is smaller than the female, being only about 2*6 

 mm. in length, it differs little from the female except that, as usual, the 

 last thoracic segment and the abdomen are smaller. 



Habitat. — On the gills of Lahrus mixtus, Lin. — the Striped Wrasse — 

 captured in the Firth of Clyde in the vicinity of Ayr, on January 30tii, 

 1900, and forwarded to the Laboratory by Mr. Robert Duthie, Fishery 

 Ofiicer, Girvan. My son (Mr. A. Scott) has taken the same species on 

 the gills of Lahrus mixtus and Lahrus macidatus captured in the 

 Irish Sea. 



This Caligus differs from any species with which I am familiar in the 

 proportional sizes of the cephalic shield and the last thoracic segment, 

 and in the peculiar form of the sternal fork. 



Genus Pseudocaligus, A. Scott (1900). 



Pseudocaligus brevipedis (Bassett-Smith). 



1896. Caligtcs brevipedis, Bassett-Smith, Ann. and Mag. Nat. 



Hist., (6), vol. xviii., p. 11, pi. III., fig. 1. 

 1901. Pseudocaligus brevipedis, A. Scott, Some Additions to 

 the Fauna of Liverpool Bay, Trans. Liverpool Biol. Soc, 

 vol. XV., p. 350, pi. IL, figs. 1-6. 

 One or two specimens of this curious form were found in the throat of 

 a specimen of the Three-bearded Rockling — Onos tricirratus — captured 

 at Dunbar, Haddingtonshire, in 1892. The copepods were only noticed 

 on the fish in August of the present year, 1901, by my son, Mr. A. 

 Scott. 



This is comparatively a small species, and differs from Caligus, 

 especially in the rudimentary character of the fourth thoracic feet. 



Genus Lepeopktheirus, Nordmann (1832). 



Lepeophtheirus pollachii, Bassett-Smith. 



Specimens of this copepod were obtained in the throat of young 

 Pollack — Gadus pollachius — sent from Girvan, Ayrshire, in May, 1901. 

 A few of them were also adhering to the tongue of the fish, and the part 

 to which they were adhering appeared to be lacerated. 



