540 PROCEEDINGS OF THE NATIONAL MUSEUM vot,. m 



of different lengths; each basal exopod segment has two small setae at its outer 

 distal corner, while the basal endopod segments are unarmed. 



Total length 4.43 mm. Enlarged cjlindrical body 3.20 mm long, 1.50 mm 

 wide. 



Male: Much smaller than the female, the body made up of ten segments, the 

 first three considerably widened, the remaining seven regularly tapering a little 

 backward. The head is fused with the first thoracic segment, which carries 

 a lateral plate or lamella on each side. The next three segments also carry 

 lateral plates diminishing in size to become mere knobs on the fourth segment. 

 The fifth segment, genital segment, and the four abdominal segments have con- 

 vex lateral margins and differ but little in length. The caudal rami are like 

 those of the female except that each has four terminal setae, the two outer 

 ones very short, the middle ones as long as the ramus. 



The first antennae arise from the dorsal surface of the head close to the 

 anterior margin and are strongly curved backward. The mouth parts and 

 swimming legs are like those of the female. 



Total length 2.35 mm. Width of first segment, including wings, 1 mm. 



EemarJcs. — So far as known, this represents the first occurrence of 

 internal copepod parasites reported from the shipworm, Teredo. In 

 view of the large number of Teredos that have been handled in the 

 coui-se of many studies of these destructive mollusks, the copepod para- 

 site here described cannot be very common or it would have been found 

 before. Concerning its occurrence, Dr. Edmondson has written me 

 as follows : 



"The copepod was first observed during the fall of 1939, when fully 

 75 percent of the specimens of Teredo niiUen Dall, Bartsch, and Kehder 

 (1938) over 30 mm in length recovered from Honolulu Harbor w^ere 

 found to be parasitized. The parasite has appeared in shipworms at 

 three additional localities about Oahu, and also in Hilo Harbor, 

 Hawaii, and at Kahului, Maui. 



"Six shipworms, five species of Teredo and one of BanJcia, in Ha- 

 waiian waters are known to serve as hosts of the parasite. 



"The female clings tightly to the lining of the infrabranchial cavity 

 of the host by means of stout, sharp mouthparts, while the male is 

 likely to be unattached in the cavity and when released from the host 

 is capable of swimming quite freely. Because of the greatly inflated 

 body the female is capable of but slight movement when detached 

 from the shipworm." 



Suborder Harpacticoida 

 Family PELTIDHDAE 



UNICALTEUTHA,' new genus 



Body broadly oval and considerably flattened, the carapace fol- 

 lowed by three dorsal epimeral plates turned ventrally on their 



^ From unicus, singular, especially in its habitat, + Alteutha. 



