276 Part 111. — Twenty -fourth Annual Report 



Both branches of the other three pairs are also three- jointed, elongated 

 and slender, the inner branches being rather shorter than the outer, as 

 shown in the drawing which represents the fourth pair (fig. 7). 



Fifth pair tolerably large and foliaceous ; basal joint somewhat 

 triangular in outline, the distal half of the inner margin which slopes 

 towards the apex is provided with three stout setae, the inner margin is 

 nearly straight and terminates in an angle, and immediately posterior to 

 this angular tooth are two apical setae, which are separated from the 

 lowermost of the three on the inner margin by a distinct hiatus, as in the 

 drawing. Secondary joint subquadrangular, its width being equal to 

 nearly two-thirds of the length, the outer and inner margins are nearly 

 parallel at the proximal end, but they taper from about the middle of the 

 joint towards the apex and there are three setae on the outer margin, one 

 on the lower inner margin and two on the apex, as shown in the drawing 

 (fig. 8). 



Furcal joints very short (fig. 9). Principal tail seta?, slender. Two 

 ovisacs. Male unknown. 



Habitat. — Granton, Firth of Forth ; dredged in an old quarry to which 

 the tide has access. Apparently rare. 



Remarks. — In some respects Amphiascus Catherines comes very near 

 Amphiascus (Dactylopus) minutus, Claus., as described and figured by G. 

 0, Sars,* but the form and armature of the fifth pair of thoracic feet are 

 totally different. Other but less obvious differences are also noticeable, 

 as, for example, in the form and armature of the mandible-palp, the 

 armature of the outer and inner branches of the fourth pair of thoracic 

 legs and in the hirsute character of the first two abdominal segments. 

 Unfortunately I have been unable to obtain the male of this form, but 

 owing to the differences mentioned I prefer meantime to regard this as a 

 distinct form from A. minutus. 



Genus Dactylopusia, A. M. Norman (1903). 

 Dactylopusia brevicornis (Claus). PI. xiv., figs. 10-18. 



1866. Dactylopus brevicornis, Claus., Die Copepoden-fauna von 

 Nizza, p. 29, Taf. iii., figs. 20-25. 



1905. Dactylopusia brevicornis, G. 0. Sars, Crust, of Norway, 

 vol. v., p. 130, pi. lxxx. 



The female of this species, like that of some others of the same group, 

 has the cephalothorax depressed and broadly ovate, but the abdomen is 

 comparatively narrow (fig. 10). Rostrum short, with a broadly rounded 

 apex. Length -77mm. (^g- of an inch). 



Anterior antennae composed of five joints, very short and stout; the 

 first three are more robust than the remaining two joints, the end joint is 

 fully twice as long as the penultimate one (fig. 11). The formula shows 

 the proportional lengths of the various joints as follows : — 



Proportional lengths of the joints, - 1 8 • 12 • 16 ' 6 • 17 

 Numbers of the joints, - - - 1 2 3 4 5 



Posterior antennae stout, two-jointed, with a short three- jointed outer 

 ramus (fig. 12). 



Mandibles stout, with an obliquely truncate apex, which is armed 

 with a few large and several small teeth. Mandible palp with a dilated 

 basal part bearing two very short uniarticulate branches (fig. 13). 



* Crustacea of Norway, vol. v., p. 154, pi. xevi, (March 1906). 



