74 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



with 250-300 joints, the edj^es of all raised distally and overlapping: 

 the succeeding joint, this character becoming- marked after the eighth 

 brachial. The distal edges of the joints are set with a row of fine 

 sharp teeth, each with a median ridge which is continued in a raised line 

 for some distance back onto the joint, giving it a longitudinall}' striate 

 appearance. All the syzygies except the proximal two or three are 

 supplied with a row of these teeth, becoming distally quite as promi- 

 nent as those on the articulations. The first brachial is trapezoidal in 

 shape, the outer edge being about twice as long as the inner; the second 

 brachial is triangular when viewed externally; the succeeding joints 

 to the tenth are quadrate, having pinnules on their shorter sides, and 

 their apposed edges rising to tubercular prominences, alternating in 

 position; from the tenth on the brachials are triangular, rather short, 

 and becoming shorter distally. S3"zygies alwa^'s in the third, eighth, 

 and twelfth brachials, and distally at intervals of 2 joints. 



The first pinnule is 20 mm. long with nearly 100 very short joints; 

 the second pinnule is 24 mm. long, both this and the first with a 

 strong comb on their distal half; the third pinnule is 25 mm. long, 

 with much more elongate joints and only the last quarter with a 

 comb; the fourth pinnule is 21 mm. long, the fifth 23 mm. long, and 

 the sixth 20 mm. long, all with much elongated joints; the fourth and 

 following pinnules bear genital glands; distally the length decreases 

 to about the twelfth pinnule, then increases again. 



This species is readily distinguished by the great length of all the 

 pinnules, and especially of the first six or eight pairs, which are 

 remarkably uniform, combined w^ith the presence of a syzj^gy in the 

 twelfth brachial. 



Color in life yellow, the cirri whitish. 



Type.—C^i. No. 22650, U.S.N. M.; from Alhatrof<s station No. 3332; 

 54° 02' 50" north latitude, 166° 45' 00" west longitude (Bering Sea); 

 406 fathoms; August 21, 1890. 



6. ANTEDON PERPLEXA, new species. 



In general similar to the preceding species, but more slender, the 

 arm joints more elongate and quadrate, the axillary considerably 

 wider than the second radial, and the third syzygy almost invariably 

 in the fourteenth brachial, rarely in the thirteenth, and never in the 

 twelfth. 



Color in life yellow or brow^nish yellow, the cirri whitish. 



r?/;;e.— Cat. No. 22611, U.S.N.M.; ivova Albatross std^iion No. 3070; 

 47° 29' 30" north latitude, 125° 43' 00" west longitude (ofi' the coast 

 of Washington); 636 fathoms; June 28, 1889. 



