392 



Part III. — Eighteenth Annual Report 



least, I prefer to leave them there. The earlier recorded form will be 

 described first. 



Description of (?) Tetragoniceps malleolata, Brady. 



The body of this copepod is elongated and slender, tapering more or 

 less gradually from the head to the extremity of the abdomen ; the 

 rostrum is short, the cephalic and thoracic appendages are moderately 

 elongate, and the entire length of the specimen figured is '89mm. (the 

 of an inch). The antennules in the female are nine-jointed ; the first 

 joint is long, and the inner distal angle is produced into a stout and 

 somewhat triangular tooth-like process; the next three joints are consider- 

 ably shorter than the first ; the last joint is about as long as the fourth, 

 but the four joints that precede the last one are small; a moderately long 

 sensory filament or asthetask springs from the end of the fourth joint as 

 shown in the drawing (fig. 10). The antennae, mandibles, and maxillae are 

 nearly similar to those in Tetragoniceps bradyi* The posterior foot-jaws 

 are three-jointed, but the end joint is very small ; there are two terminal 

 setse — one moderately elongate, the other smaller and slightly plumose. 

 The outer branches of the first to the fourth pairs of thoracic feet are all 

 three-jointed, but all the inner branches are two-jointed. In the first 

 pair, which are comparatively slender, the inner branches are elongate, 

 the first joint being rather longer than the entire length of the outer 

 branches ; the second joint, which is scarcely half the length of the first, 

 carries two stout terminal setse — the inner one being the longer ; there is 

 also a small seta on the lower half of the inner edge of the first joint. 

 The inner branches of the second, third, and fourth pairs are considerably 

 shorter than the outer branches ; those of the second and third pairs 

 extend slightly beyond the second joint of the outer branches; but in the 

 fourth pair the inner scarcely reach the middle of the second joint of the 

 outer branches, and this difference is owing, in part at least, to the outer 

 branches of the fourth pair being proportionally more elongated than the 

 outer branches of the two preceding pairs. The fifth pair of feet are two- 

 jointed ; the basal joint is foliaceous and somewhat triangular in outline ; 

 it is provided with three small setse on the lower half of the inner margin, 

 and with a small apical seta. The second joint is elongated and narrow, 

 and it tapers gradually till it becomes somewhat attenuated at the 

 extremity; this joint is provided with a few small setae on the outer edge 

 and one on the inner, and also with a slender terminal hair. The caudal 

 segments are slender, and about as long as the last abdominal segment. 



The female carries one ovisac, which contains a few moderately large 

 ova arranged in a single series. 



The male differs little from the female, except that the antennules are 

 hinged, and otherwise modified for grasping ; the fifth pair of feet are 

 also less fully developed ; the basal joint is sub-quadrate, and the inner 

 portion slightly produced distally and furnished with two moderately 

 stout, spiniform apical setse ; the secondary joint is sub-cylindrical, and is 

 armed with a moderately stout and elongated spine near the distal end of 

 the inner margin. The first abdominal segment in the male bears slightly 

 produced lateral appendages provided with three moderately long setae ; 

 these appendages are situated immediately posterior to the fifth thoracic 

 feet. 



Habitat. — Firth of Forth, off St. Monans ; rather rare. 



Tetragoniceps brevicauda, sp. n. (PL XIV., figs. 18-22.) 



As already stated, this copepod does not differ very greatly from 

 * Vide Part III. Tenth Ann. Report Fishery Board for Scot!., p. 253, PI. IX. (1892). 



