A? BRITISH COPEPODA. 
spinulosa have not been seen; but the points of differ- 
ence, as shown in the plates, seem to me to be too 
well marked to allow of the two forms being brought 
under one specific name. 
Genus 12. Detavatta, Brady (1868). 
Delavalia, Brady. Nat. Hist. Trans. Northumberland and Dur- 
ham, vol. iii (1868). 
Animal hke Dactylopus in general form; rostrum 
short and blunt, abdomen of the female 5-, of the male 
6-jointed, tail-segments distant and rather divergent: 
anterior antennz shorter than the first body-segment, 
in the male hinged (Plate LI, tig. 3), but destitute of 
a vesicular swelling, 8-jomted; inner branch of 
posterior antennz composed of two or three joints; 
mandibles well developed, basal joint of the palp large, 
and giving origin to two long, slender, 1-jointed 
branches. Maxillar palp well developed, multilobular ; 
first foot-jaw composed of several digitiform seg- 
ments, a small marginal 2-lobed palp, and a long 
terminal claw. Second foot-jaw forming a slender 
clawed hand. All the branches of the four pairs of 
swimming-feet 3-jointed, except the inner branch of 
the first pair, which has only two joints. Basal joint 
of the fifth pair of feet very short and broad, second 
joint leaf-lke, ovate or subovate; ovisacs two, large, 
and containing a small number of large ova. 
