COPEPODS OP THE WOODS HOLE EEGION 423 



the genital segment, dorsal plates siibtriangular, separated by a sinus 

 of medium width. Genital segment orbicular, its lateral margins 

 very convex and dentate, its posterior corners produced into slender 

 conical processes, reaching beyond the tips of the caudal rami, and 

 without spines except at the tip. Abdomen 2-segmented, basal seg- 

 ment lunate, produced laterally into curved lobes, each larger than 

 the segment itself; caudal rami twice as long as wide. Total length, 

 8-9 mm. 



Male. — Unknown. 



Rem,arks. — Kr0yer did not have a male of this species, as he 

 claimed, but a female without egg strings, as can be seen from Bald- 

 win's figure here given. The two specimens described by Bassett- 

 Smith as the female of Kr0yer's male are evidently an entirely differ- 

 ent species, as shown by the shape and proportions of the genital and 

 first abdominal segments, and the new specific name maculatus may 

 be suggested for it in allusion to the six bright red pigment spots on 

 the dorsal surface of the genital segment, which are found in no 

 other species. Although discovered and figured bj'^ Rathbun in 1885, 

 this is the first time the species has been reported from our American 

 shores. 



ALEBION CBASSUS, new species 

 Plate 26 



Occun^ence. — Two females and a male were taken from the outside 

 of the hammerhead shark {Sphyrna zygaena) at Woods Hole, August 

 1, 1913. The best female has been made the holotype with U.S.N.M. 

 No. 56614. 



Color. — Body light yellowish brown, becoming darker in the 

 thicker portions over the digestive and reproductive organs; eye red. 



Female. — Carapace orbicular, wider than long; frontal plates nar- 

 row with a circular median sinus ; lateral lobes broad, curved strongly 

 inward at their tips, and reaching considerably behind the median 

 lobe. On the inner margin of each of these lateral lobes is a double 

 flap or transparent border, one part dorsal and one part ventral. 

 To the dorsal flap, near the tip of the lobe, is attached a small tab 

 turned backward and lying on the dorsal surface of the lobe. The 

 median lobe of the carapace is broad and slightly concave on its 

 posterior margin, with two or three small spines at each corner. 

 Grooves separating the areas of the carapace arranged like the letter 

 H as in other species, the median area exceptionally broad. Eye so 

 small as to be detected only by transmitted light. 



Fourth segment a little more than half as wide as the genital seg- 

 ment, its dorsal plates orbicular, extending well onto the genital 

 segment, and separated by a wide posterior sinus. Genital segment 

 five-eighths as wide as carapace, widest behind the center, where its 

 lateral margins are convex and are armed with a frinere of stout 



