142 - Part III. — Twenty-third Annual Report 



The female of this species was described and figured by Dr. Wolfenden 

 in the Journal of the Marine Biological Association for January, 1902, 

 but the male appeared to be unknown. 



The male specimen (fig. 1), which I now propose to describe, agrees so 

 closely with Dr. Wolfenden's definition and figures of the female that, 

 after making allowance for sexual differences, I have no hesitation in 

 ascribing it to the same species. 



The cephalothorax is robust, and appears to be composed of only four 

 segments, but the fifth is so small as to be almost entirely obscured by 

 the fourth ; the abdomen is slender and much shorter than the body ; 

 rostrum not much produced. The length of the specimen figured is 

 about '8mm. (about ^ of an inch). 



Antennules (fig. 1) moderately slender, except towards the proximal 

 end ; they are shorter than the cephalothoracic segment, and composed of 

 seventeen joints ; the basal joint is large and stout and rather more than 

 half as long as the entire length of the remaining joints, which are all 

 short — the tenth, fourteenth, fifteenth and last are, however, rather 

 longer than any of the other twelve. The formula shows approximately 

 the proportional lengths of all the joints : — 



Proportional lengths of the joints, 58 •5 , 6*4-3'4-4 , 7 , 7 , 9'6-6-7 , 9* 12-8-10 

 Numbers of the joints, - - - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 



Posterior antennae, outer ramus scarcely so long as the inner one, and 

 composed of five joints — the third and fourth joints are very small and 

 sparingly setiferous (fig. 3).* Mouth appendages similar to those of the 

 other described species. 



All the four pairs of swimming feet (figs. 4-7) are also similar to those 

 of the other described species, except that they are rather more hispid, but 

 especially the inner branches of the fourth pair, and the outer branches 

 also to some extent. In this pair the joints are more or less covered 

 with minute prickles, as shown in the drawing (fig. 7), and the same 

 character distinguishes the fourth pair in the female described and 

 figured by Dr. Wolfenden. 



Fifth pair are elongated and unequal on the two sides ; the left leg 

 is long and slender, for though the first and second joints are short, 

 the other is of considerable length, and is probably longer than the 

 drawing shows it, as the extremity is apparently slightly damaged; a 

 dense fringe of small delicate hairs extends along part of the proximal 

 half of the inner margin of the slender end joint, and terminates distally 

 at a small hook-like process (fig. 8). The right leg is considerably dilated 

 at the proximal end of the second joint, but becomes attenuated towards 

 the distal extremity ; the third joint is narrow, and terminates interiorly 

 in one or two finger-like processes ; while the end joint, which is very 

 slender, and tapers gradually to a pointed apex, is furnished with a small 

 process exteriorly near the proximal end, as shown in the drawing (fig. 8.). 

 The abdomen is composed of five moderately short segments, and the 

 furcal joints are also short (fig. 9). 



Habitat. — Firth of Forth, west of Queensferry. Dredged Nov. 17, 

 1893, but only now described and figured. 



Remarks. — One of the characters peculiar to the genus Pseudocyclopia 

 is the presence of a long, moderately stout spine which springs from the 

 inner distal angle of the first basal joint of the third pair of legs and 

 reaches to about the end of the inner branch, as shown in figure 6. 



* Dr. Wolfenden describes the posterior antennae as one-branched, but the outer ramus 

 so characteristic of the Pseudocyclopiidae as of the other Calanoida had probably become 

 accidentally detached, and had thus given to the posterior antenna? an appearance some- 

 what unique among Calanoids. 



