FREE-SWIMMING COPEPODS OF THE WOODS HOLE REGION. 
179 
tiguous. Last thoracic segment, produced into longer points, the one on right side being distinctly 
longer than that on left. Abdomen consisting of 5 segments; anal segment very short, first segment 
without hairs on its sides. Anterior antennae reaching to base of furca; joints 16 and 17 of about equal 
length, the latter provided with a recurved spine ou its anterior basal surface; teeth on eighteenth 
joint uniform, somewhat larger and more hook-like than teeth on fused nineteenth and twentieth, 
which are fully one third longer than twenty-second joint and terminate in a distinct point distally. 
Bristles on joints 23 and 24 to 25, not plumose. For structure of fifth pair of feet, see fig. 16, d and e. 
Coloration, transparent, without pigment. Length, 1.75 to 2 mm. 
This species appears to be sufficiently distinct from any of the described 13 species of Labidocera, 
nor can it be referred to any of the insufficiently described and figured species of Pontella in Dana’s 
monograph. Of known forms it approaches L. nerii Krdyer, but may be distinguished by the sym- 
16. Labidocera (estiva new spades-, a, female, dorsal aspect; 6, male, dorsal aspect; c, male, right anterior autenoa; 
d, male, right fifth foot; e, male, left fifth foot; /, female, fifth foot. 
metrical genital segment of female and the acute tooth terminating inner ramus of fifth foot. The male 
may be distinguished from the male nerii by the asymmetry of the last thoracic segment and many 
differences in configuration of fifth pair of feet. (Conf. Giesbrecht’s fig. 45, pi. 24.) 
L. astiva was very common in the tow taken from the Fish Commission wharf at Woods Hole during 
July and early August, 1899. 
PONTELLA Dana. 
Fourth and fifth thoracic segments separated; head with lateral hooks ; one pair of dorsal eye- 
lenses and a rostral lens in front of ventral eye, the latter sometimes thicker in male than in female ; 
rostral prong stout; last thoracic segment with pointed lateral corners, not always symmetrical; 
abdomen of female -with 2 or 3 segments, asymmetrical; that of male (apart from one-sided 
genital orifice) symmetrical. Anterior antennm of female 24-jointed; right one of male with fused 
thirteenth and fourteenth, nineteenth to twenty-first, twenty-second to twenty-fifth joints. Mandib- 
ular blade with hooked, jjointed teeth; second basal joint of maxilla about 14 times as long as 
second internal lobe; third internal lobe present. Posterior maxilliped 7-jointed; inner ramus of 
first pair of feet 3-jointed. 
