Mr. Lubbock on two new Subgenera of Calanidse. 209 



Fifth pair of legs (figs. 10 & 11). 



Male. The left leg consists of four joints. The first two short, 

 the third longer, and the fourth again shorter ; the apex is swollen 

 and covered with delicate papillae. Externally near the base the 

 terminal segment bears a strong hair, and near the middle a 

 small one. Internally it has a row of hairs near the base, and a 

 large very delicate tuft. This tuft appears to be very constant ; 

 it exists in all three species of Labidocera, and a similar one is 

 figured in Templeton's paper on Anomalocera. Length ^V inch. 



The right leg also consists of four segments, and is very similar 

 to that of L. Patagoniensis and Darwinii. The third joint has the 

 basal spine rather more curved, and bears also a triangular mem- 

 branous lobe with the angles rounded off and contracted at the 

 base into a sort of neck ; at its base is a small hair. The 

 apical joint also has a triangular projection with a broad base, 

 and bears four small hairs. 



This fine species being the only one in the subgenus, no spe- 

 cific description need be given. 



Its length is \ inch. 



Colour ? 



It comes from the South Pacific Ocean, and seems to be rare ; 

 at least I have only one specimen, which is a male ; the female 

 is therefore as yet unknown. 



My single specimen of L. magna (as well as more than one 

 of L. Patagoniensis) is attacked by a disease, showing itself as 

 white spots which spread over the back. This appears to be 

 similar to that which so commonly destroys Chirocephalus dia- 

 phanus. The back of the common Daphnia Pulex also is often 

 rendered quite white by a substance formed under the shell, and 

 which consists of innumerable very minute, triangular or pear- 

 shaped bodies, each about -^-^^q inch long, and -g-^^-^ broad at the 

 thicker end. 



EXPLANATION OF PLATE X. 



Fig. 1. Labidocera (Ivella) Patagoniensis. Male. 



Fig. 2. Ditto ditto. Female. 



Fig. 3. Ditto Second pair of antennae. 



Fig. 4. Fifth pair of legs. Male. Right. 



Fig. 5. Ditto ditto. Terminal joint of the left. 



Fig. 6. Fifth pair of legs. Female. 



Fig. 7- Abdomen. Female. Without the appendage. 



Fig. 8. Labidocera {Iva) magna. Rostrum. 



Fig. 9. Prehensile apparatus of the right anterior antenna of the male, 



much magnified. 

 Fig. 10. The i-ight leg of the fifth pair in the male. 

 Fi^. 11. The left ditto ditto. 



The drawings were done with a camera Incida. 

 Ann. S^ Mag. N. Hist. Ser. 2. Vol. xi. 14 



