14 



MARINE AND FISHERIES 



6-7 EDWARD VII., A. 1907 



large size and by its transparent pale pink colouration. Fig. 4, Plate VI., is after 

 Giesbrecht's figure of this species, and serves to call attention to the arrangement 

 of the appendages in the order. 



Pseudocalanus ehngatus Boeck (Plate VI., fig. 5) was exceedingly abundant in 

 July and August, and can be readily recognized by the orange pigment and the green 

 of the vulvar region, as well as by the morphological features described by Giesbrecht. 

 The eggs, about 100/x, in diameter, are in a loose cluster, from 1 to 13, and sperma- 

 tophores of SlOfx length were frequently observed with a longer or shorter tube. The 

 individuals frequently carried clusters of a diatom {Lichmophora, sp.). As Gies- 

 brecht has noticed, the larva of H. appendiculatus (p. 12) is found in this copepod, 

 but it^lso occurs in Acartia hifilosa. 



CENTROPAGIDAE. 



Both Oenfropages hamatus Lilljeborg (Plate V., fig. 6), and G. typicus Lilljeborg 

 were observed, the latter much less abundant and appearing considerably later than the 

 former. They may be readily distinguished by the different armature of the genital 

 segment of the female. 



Temora longicornis, O. F. Muller, a northern form, was also abundantly repre- 

 sented. 



PONTELLIDAE. 



Tortanus. — This generic name has recently been substituted by Giesbrecht for 

 Corynura (preoccupied),, and expresses the remarkable distortion of the abdomibal 

 region which characterizes the genus. One species of this genus (T, discaudatus I. C. 

 Thompson and H. Scott), Plate VI., fig. 9, was exceedingly common at Canso from the 

 end of July to the middle of August. It was first recorded by the authors named from 

 the Gulf of St. Lawrence and afterwards observed by Wheeler at Wood's Hole and des- 

 cribed as Corynura humpusii, 1 have little to add to the excellemt account furnished 

 by him except to suggest an explanation for the distortion of the furcal region. The 

 second post-genital segment of the female carries a bunch of stiff hairs adjacent to that 

 on the first, while the second abdominal segment of the male has certain grooves on 

 the chitinized projection formed by the right posterior angle, as well as a few scattered 

 bristles. In the right antenna of the male the first joint distad of the knee (19-21) 

 carries two pectinate ridges, while the iTth and 18th joints have one each (fig. 11). 



The explanation for the distortion of the abdominal region of the female (which 

 is also transmitted in a less degree to the male) is furnished, I believe, by the mode of 

 attachment of the spermatophore, which I had occasion to observe very frequently. The 

 spermatophore itself is over 1 mm. long by 125 wide. It is attached to the genital 

 segment, in the ordinary way by a conical cement piece, but a much larger piece of 

 yellowish cement is plastered on to the large right furca and its spine, and is con- 

 nected with the beginning of the efferent ca;nal of the spermatophore by a solid cord 

 of cement of the same appearance (fig. 10). 



Some cases were noticed in which an attempt had been made to attach a, second 

 spermatophore ; in such the supplementary supporting patch of cement did not succeed 

 in fielding anchorage. 



SUBORDER PODOPLEA. 

 OYOLOPIDJE. 



Oithona plumifera Baird (fig. 8) is one of the commonest forms of this section, 

 and apart from its form can be recognized by the bright-red elongated eye-spot and a 

 certain faint orange tinge in the abdomen. The spermatophores are pyriform, with a 

 short stalk, and measure about 70, a. 



