of the Fishery Board for Scotland. 169 



six-jointed, sparingly setiferous ; the fourth joint is considerably shorter 

 and the end joint longer, than the others, as shown by the formula — 



Proportional lengths of the joints, 18 • 10 • 18 • 5 • 9 • 22 

 Number of the joints, 1 * 2 ' 3 * 4 * 5 * 6 



Antennae somewhat similar to those of Cletodes lata (PI. V. fig. 1). 

 Posterior foot-jaw short, stout, and armed with a stout curved terminal 

 claw : the claw is fringed with hairs on the distal half of the inner margin ; 

 a setiferous spine springs from the upper distal angle of the first joint; 

 the second joint, which is somewhat dilated and gibbous below, is fringed 

 with small hairs ou both margins (PI. III. fig. 24). The first joint of the 

 outer branches of the first pair is nearly equal to the combined length of 

 the second and third joints ; the outer branches are also armed with long 

 slender marginal spines and small spiniform setae, — the end joint bears 

 two marginal and one*long slender terminal spine; the same joint is also 

 furnished interiorly with two very long and plumose sub terminal setae, 

 and a moderately long setae, also plumose, springs from the lower distal 

 half of the inner margin of the second joint; the inner branches, which 

 are two-jointed, and reach to about the end of the second joint of the 

 outer branches, have the first joint short but moderately stout, while the 

 second joint is slender and more elongate, the first joint bears four short 

 plumose setae on the inner distal angle, and the second joint is furnished 

 at the extremity with one short and one very long plumose setae and a 

 slender spine ; a stout setiferous spine, which reaches to about the middle 

 of the end joint of the inner branch, springs from the inner distal angle 

 of the second basal joint, and a similar but rather more slender spine 

 springs from the outer angle of the same joint (PI. IV. fig. 2). The fourth 

 pair are somewhat similar to the same pair in Cletodes lata, but the 

 marginal spines of the outer branches are much shorter and stouter (PI. 

 IV. fig. 3). In the fifth pair the inner portion of the basal joint is pro- 

 duced into a subcorneal lobe bearing at its apex a long stout and coarsely 

 plumose seta, while a smaller seta springs from the outer margin and 

 close to the apical seta ; secondary joint elongate, narrow and armed with 

 one long terminal and three rather shorter marginal setae ; the setoe are 

 all more or less curved, and the uppermost of the three marginal setae is 

 spiniform and setiferous (PI. IV. fig. 25). Caudal stylets as in Cletodes 

 lata. 



Male. — The male differs little from the female, except in the structure 

 of the antennules and fifth pair of thoracic feet. The antemiules are 

 apparently nine-jointed and rather more slender than those of the female, 

 and are modified to form powerful grasping organs (PI. III. fig. 23). 

 The fifth pair in the male are scarcely half the size of those of the female, 

 but somewhat similar in form ; the two plumose setae on the inner 

 portion of the basal joint are much shorter ; the secondary joint bears 

 only two small marginal setae, while the apical seta is of considerable 

 length and plumose (PI. III. fig. 26). 



Habitat. — In shore pools, as well as in deep water, Firth of Forth, and 

 Port Erin, Isle of Man. 



Remarks. — This species has been known to us since 1891, and in the 

 Tenth Annual Eeport of the Fishery Board for Scotland, Part III. p. 257, 

 it is referred to as a doubtful variety of Cletodes lata. During recent 

 months the same two forms, Cletodes lata and the species now described, 

 have again been the subject of careful study, with the result that we are 

 now satisfied that they are quite distinct. They differ in the structure of 

 the antennules, and very markedly in the form of the posterior foot-jaws ; 

 they also differ in the proportional lengths, and in the armature of the 



