321 



at the base. Genital segment in female scarcely subdivided at all. Caudal rami 

 comparatively short. Anterior antennae slender, 7-articulate, with the 2nd joint 

 much the largest, and the terminal part distinctly 3 -articulate; those in male 

 slightly hinged. Posterior antennae with the outer ramus very small and rudimentary. 

 Mandibular palp small, uniarticulate. Maxillae and anterior maxillipeds normal. 

 Posterior maxillipeds quite rudimentary, being replaced by 2 small immobile 

 lamellae intercalated between the bases of the anterior maxillipeds. Natatory legs 

 with the inner ramus distinctly bi-articulate, that of 1st pair larger than that of 

 the 3 succeeding pairs; 4th pair exceeding the other pairs in size, the outer ramus 

 being considerably elongated. Outer ramus of 2nd pair and inner ramus of 3rd 

 pair conspicuously transformed in male. Last pair of legs very small lamelliform. 

 2 ovisacs present in female. 



Remarks. This genus was removed by Prof. Brady from the Harpacticoida, 

 and described under the head of the group Poecilostoma Thorel. There cannot 

 be any doubt that such an arrangement is quite untenable, and the genus has 

 subsequently been placed by Th. Scott among the Harpacticoida. The structure 

 of the mouth-organs was not made out by Prof. Brady, and Th. Scott, who carefully 

 examined these organs, has fallen into a strange error, as regards the interpretation 

 of these parts. What he describes, though with some hesitation, as the maxillae, 

 are evidently the lateral lobes of the posterior lip, and the parts described as 

 the anterior and posterior maxillipeds are in reality respectively the maxillae and 

 the anterior maxillipeds, the slight rudiments of the posterior maxillipeds having 

 apparently escaped his attention, or being perhaps wrongly represented as parts 

 of the so-called "labium" (fig. 8). 



208. Cylindropsyllus laevis, Brady. 



(PJ. CCXV). 



t'ljtindropsyttus Icevis, Brady, Monograph of British Copepoda, Vol. Ill, p. 30, PI. LXXXIV, 



figs 18. 



Specific Characters. Female. Body exceedingly slender and elongated, and 

 perfectly cylindrical, being of the very same width throughout. Cephalic segment 

 somewhat exceeding in length the 2 succeeding segments combined, rostrum small, 

 triangular in form. The 3 succeeding segments without any distinct epimeral 

 plates; last pedigerotis segment somewhat larger than the preceding one. Uro- 

 some slightly exceeding in length the anterior division, genital segment not much 

 larger than the others, and without any visible subdivision; last segment a little 

 longer than the preceding one, and having the anal opercle rather prominent, and 



13 Crustacea. 



