NO. 1573. PARASITIC COPEPODS— WILSON. 371 



either side of the median Hne, three pairs on the third legs circular in 

 form and arranged in a triangle at some distance from the median line 

 on either side. There is also a median impaired pad on the anterior 

 margin of these legs, transversely elliptical in form. 



Mouth-tube long and slender; second maxillfe laminate, rather 

 narroW; and tapering to a rounded point. First maxillipeds stout, the 

 anterior terminal claw more than twice the length of the posterior, 

 both claws fringed with hairs. Second maxillipeds not much swollen, 

 the terminal claw semicylindrical, the flat side shutting down against 

 a pair of spherical knobs on the basal joint. All the swimming legs 

 biramose; rami of the first pair two-jointed; basal joint of the exopod 

 as long as both joints of the endopod; terminal joint circular in out- 

 line, half as long as the basal; endopod joints the same length. 



Exopods of second, third, and fourth legs three-jointed, endopods 

 two-jointed, the joints thoroughly fused in the fourth pair. 



Endopod joints subequal in the three pairs; basal exopod joint of 

 the second pair longer than the two (equal) terininal joints; basal 

 joint in the third pair a little longer than either of the others; the 

 three joints in the fourth pair subecpial. 



Setae and spines arranged as follows: First exopod, 0, 1 ; 4, III: 

 endopod, 0, 0; 4, 0: second exopod, 1, I; 1, I; 4, III: endopod, 

 0, 0; 3, 0: third exopod, 1, I; 1, I; 6, II: endopod, 0, 0; 3, IV: 

 fourth exopod, 0, I; 0, I; 0, I: endopod, 0, 0; 0, 0. 



Total length, 9 mm.; length of carapace on mid-line, 3.25 mm.; 

 width, 4.57 nnn.; length of free segments, 1.5 mm.; length of third 

 dorsal plates, 2.85 mm.; length of genital segment, 4.3 mm.; width 

 of third plates, 4.5 mm. 



Color of preserved specimens a yellowish brown, probably discolored 

 by the alcohol. 



(denticulatus, armed with minute teeth, referring to the margins of 

 the third dorsal plates.) 



The U. S. National Museum collection contains a single specimen, 

 the original type described by Smith in 1874. It was taken from 

 Atwood's shark, Carcharodon carcharias captured in Vineyard Sound, 

 Woods Hole and is numbered 6169. Smith gave a brief description 

 of the species without any figiu"es, and it has remained um-ecognized. 



The full description and figures here given should establish its 

 validit}^ It can be readil}^ recognized by the spines or teeth on the 

 third dorsal plates and by the projecting fifth legs. 



ECHTHROGALEUS TORPEDINIS, new species. 

 Plate XXI. 



Type.— Cat. No. 11350, U.S.N.M. 



Female. — Body short and wide; length to width as 5 to 3. Cara- 

 pace orbicular, considerably wider than long, even including the pos- 



