COPEPODS OF THE WOODS HOLE REGION- 235 



segment and is armed with six setae, the second outer one much 

 elongated. Total length, 0.55-0.65 mm. 



Male. — Smaller and more slender than the female; the first an- 

 tennae are geniculate, the first segment beyond the hinge consider- 

 ably enlarged, the end segment curved into a sort of claw. The outer 

 spines of the exopods of the swimming legs are lengthened and 

 widened and bluntly pointed. The first endopod is a little longer 

 than the exopod, the second endopod has a short stout spine at the 

 outer distal corner of the end segment, the third endopod is 3-seg- 

 mented, the basal segment very short, the middle segment with a row 

 of short hairs across its surface and a curved spine on its inner mar- 

 gin, the end segment is spherical, with two unequal apical setae, the 

 fourth endopod is like that of the female. 



The fifth legs are much smaller than in the female ; the distal seg- 

 ment reaches the tip of the basal expansion, is truncated and armed 

 with three setae, the middle one the longest, and small spinules on the 

 lateral margins. The basal expansion is broadly rounded with three 

 apical setae and two spinules on each lateral margin. Total length, 

 0.4-0.5 mm. 



Remarks. — This species may be told by the structure of the fifth 

 legs in the female and by the endopod of the third legs in the male. 

 It was quite abundant in the two ponds mentioned above but was 

 found nowhere else. 



Genus MARSHIA Herrick, 1895 



Bod}^ slender and cylindrical, metasome only slightly wider than 

 the urosome ; head fused with the first segment and much shorter than 

 the rest of the metasome; urosome 4-segmented in female, 5-seg- 

 mented in male ; caudal rami much longer than wide, apical setae of 

 moderate length. First antennae 6-segmented, third and fourth seg- 

 ments much enlarged in male, aesthetask on fourth segment extending 

 beyond the tip of the antenna; exopod of second antenna wholly 

 lacking; exopods of first 4 pairs of legs 3-segmented, endopods 

 2-segmented, the two segments of fourth endopod sometimes fused; 

 fifth legs apparently 1-segmented, the two segments being completely 

 fused, and the outer lobe of the basal segment often obsolete. One 

 species found here. 



MARSHIA BREVICAUDATA Herrick 



Figure 157 



Marshia breiicaudata Hekrick, Copepoda of Miuuesota, p. 137, pi. 32, figs. 6-13, 

 1895. 



Occurrence. — Five females and a male were obtained from the 

 small lily pond south of Ashumet Pond, Falmouth, July, 1926; a 

 single female from the south pond on Penikese Island, August, 1926. 



