17 



7. Canuella perplexa, Scott. 



(PI. VIII & IX). 



Canuella pcr/i/f.i'd, Th. Scott, Notes on Copepocla from the Firth of Forth. Ann. of Scottish 



Nat. Hist, 1893, p. 92, PI. II, figs. 13. 



Syn : Lonyipedia coronata $ Brady (not Claus). 



Specific Characters. Female. Body of almost uniform width throughout, 

 or very slightly attenuated behind, with rather deep and conspicuous instrictions 

 between the segments. Cephalic segment comparatively small, somewhat vaulted 

 above, and with the lateral parts but slightly expanded; rostral plate narrowly 

 rounded at the tip. 1st segment of metasome well defined, though much shorter 

 than the others; last segment scarcely narrower than the preceding one. Urosome 

 much shorter than the anterior division of the body, genital segment but slightly 

 dilated in its anterior part; the 3 posterior segments gradually diminishing in size. 

 Caudal rami scarcely twice as long as the last segment, greatly divergent, and 

 gradually tapering distally; apical setae minutely ciliated, the middle one about 

 twice as long as the outer, and equalling in length the urosome. Anterior an- 

 tennae rather robust, and consisting of 5 articulations, some of the setae very 

 strong and coarsely pectinate. Posterior antennas with the outer ramus fully as 

 long as the inner, some of the setse very strong, almost spiniform. 1st pair of 

 natatory legs considerably shorter than the succeeding ones, spines of outer ramus 

 rather elongated; 2nd pair with the first 2 joints of the inner ramus considerably 

 produced at the inner corner. Last pair of legs extremely minute, each forming 

 a thin plate edged with 4 setse, the innermost but one the longest and distinctly 

 plumous. Ovisacs large, rounded oval in form. 



Body semipellucid, of whitish colour, with a faint yellowish tinge. 



Length of adult female 1.30 mm., of male 1.25 mm. 



Ih'inarl's. Mr. Th. Scott first called attention to the fact that Prof. 

 Brady, in his Monograph of the British Copepoda, has, under the name of Longi- 

 pediu t-oronata Glaus, confounded 2 entirely different Copepoda, the one, regarded 

 by him as the male sex, being in reality a female Longipedia (= L. Seotti G. 0. 

 Sars), whereas that recorded as the female of Longipedia coronata is the form here 

 under discussion. This form was then described by Th. Scott as the type of a new 

 genus under the above name, and its differences from Longipedia were pointed out. 

 The most conspicuous of these differences is unquestionably the presence of 2 

 diverging ovisacs. a feature, indeed, very seldom met with in the Harpaeticoid 

 group; and it is apparently this anomalous character which has given rise to the 

 specific name perplexa proposed by that author. 



3 Crustacea. 



