NO. 1573. PARASITIC COPEPODS-WILSON. 373 



inward toward each other, so that the}^ He across the mouth tube 

 hke a pair of folded hands. Further back on either side, opposite the 

 base of the first niaxilhpeds, is a flattened spine, larger than the max- 

 illa and pointing backward. 



Second maxillipeds with a stout but rather short terminal claw, 

 and two large corrugated knobs on the basal joint against which the 

 claw shuts. Swimming legs biramose and of the usual pattern, but 

 with the plumose setfe on the terminal joints better developed than 

 in coleoptratus. The arrangement of the spines and set» is as fol- 

 lows: First exopod, 0, 1; 6, 0: endopod, 0, 0; 3, 0: second exopod, 

 1, I; 1, 1; 5, II: endopod, 0, 0; 4, III: third exopod, 0, I; 1, I; 6, III: 

 endopod, 0, 0; 4, 0: fourth exopod, 0, I; 0, I; 0, VII: endopod, 0, 0; 

 0, 0. 



Outside of the base of the exopod of the fom-th legs and inside of 

 the base of the endopod of the third legs is a small papilla armed with 

 a long and flexible spine, similar to those found in Perissopus. The 

 fifth legs are larger than in coleoptratus, but not as large as in denti- 

 culatus, and their tips just reach the margins of the posterior lobes. 



The oviduct is coiled once in the usual fashion, the vulva; opening 

 just beneath the base of the abdomen. The cement glands are large 

 and are arranged like parentheses marks on either side of the mid-line; 

 their posterior ends are enlarged and bent inward nearly at right 

 angles. The semen receptacle is just in fi'ont of the base of the 

 abdomen, with the vagina? opening side by side at the mid-line. The 

 spermatophores are fastened on either side of the genital segment, 

 outside and in front of the vulva, and the duct from each crosses the 

 mid-line and empties into the vagina on the opposite side of the body. 



Total length, 1:3 mm.; length of carapace on mid-line, 4 mm.; 

 width of same, 6.5 mm.; length of fi'ee segments, 2 mm.; length of 

 third dorsal plates, 5.65 mm.; width of same, 8 mm.; length of 

 genital segment, 7.38 mm.; width of same, 7 mm.; length of abdo- 

 men, without anal laminae, 2.5 mm.; length of egg-strings, 40 mm. 

 Color a dark cinnamon brown, uniform over the entire body. 



{torpedinis, the name of the host.) 



The U. S. National Museum collection includes two lots, both ob- 

 tained fTom the Torpedo, common along our Atlantic coast, Torpedo 

 occidentalis. The fii-st is Cat. No. 6187, U.S.N.M., and includes two 

 females taken from one of the pectoral fms of a Torpedo captured at 

 Woods Hole in 1875. The other lot is Cat. No. 11350, U.S.N.M., and 

 includes seven females taken from the ventral fins of a Torpedo cap- 

 tured at Provincetown, Massachusetts, October 20, 1885. 



