34 PR0CEEDI1S-G8 OF THE NATIONAL MUSEUM. vol.37. 



Cirri XXX, 8G, 50 mm. long, very long and slender, slightly taper- 

 ing distally; first joint short, second twice as broad as long, the fol- 

 lowing gradually increasing in length to the fifth or sixth, which is 

 squarish, and still further increasing to the thirteenth or seventeenth, 

 which is about half again as broad as long, or sometimes slightly 

 longer, after the nineteenth to twenty-sixth decreasing rather rapidly 

 in length, soon becoming twice as broad as long, and even shorter 

 terminally; joints from about the seventh or eighth to twenty-fifth 

 with the median portion of the ventral edge produced into a long 

 slender curved overlapping spine, as in P. trichopoda, this reaching 

 a maximum size on the tenth to the thirteenth joints and then grad- 

 ually dying away distally; as the ventral spines on the cirrus joints 

 die away, a slight prominence begins to appear on the distal edge in 

 the median line which gradually becomes a prominent tubercle, and 

 encroaches more and more upon the dorsal surface of the joints, 

 becoming the broad, high, curved, carinate dorsal spine characteristic 

 of the terminal joints of the cirri in all the species of this genus. 



Ends of the basal rays visible as small dorso-ventrally elongate 

 tubercles in the angles of the calyx ; radials short, of equal height all 

 around the calyx, four or five times as broad as long, with a trace of 

 a broad median tubercle; IBr^ oblong, four times as broad as long, 

 laterally united in the basal half; IBr^ (axillary) very broadly pen- 

 tagonal, two and one-half times as broad as long, with a slightly 

 produced lateral border, and, like the IBr^, faintly carinate; IIBr2; 

 IIIBrS, developed exteriorly; division series externally with slightly 

 produced ventro-lateral edges. 



Thirty arms, 80 mm. long, resembling in general those of P. tricho- 

 poda,, but somewhat more compressed and deeper proximally, and 

 sharply rounded instead of carinate distally. 



Pinnules essentially as in P. trichopoda^ but slightly stouter. 



In general shape this species is unique in the genus, resembling 

 such species of Pacliylometra as P. angusticalyx,' very narrow at 

 the radials and IBr^ (5 mm.), the width increases rather rapidly 

 to about the seventh brachial (20 mm.), giving the dorsal part of 

 the animal the appearance of being strongly constricted and dispro- 

 portionately small. 



Type-specimen. — Cat. No. 25518, U.S.N.M., from Albatross sta- 

 tion 5179; between Tablas and Romblon, Philippine Islands; 37 

 fathoms. 



