84 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



PI is 13 mm. long with 20 segments, moderately flexible, tapering gradually and 

 evenly from the base to the tip, which is not especially delicate. The first four segments 

 are about as long as broad and those succeeding are somewhat longer than broad, mostly 

 about half again as long as their proximal width. The first segment has the distal 

 border slightly convex. The second and third segments have the distal dorsal angle 

 extending somewhat beyond the base of the segments succeeding, and in the case of the 

 third somewhat produced. The fourth and following segments have both distal angles 

 extending slightly beyond the base of the segments succeeding, and in the last 8 or 9 

 segments the sides diverge slightly so that in this portion of the pinnule both the proxi- 

 mal and distal profiles are serrate. The outer surface of the pinnule is rather narrowly 

 rounded. 



P 2 is 7 mm. long with 12 segments; it is slightly less stout basally than P : and like 

 that pinnule tapers regularly to the tip. The first two segments are slightly broader 

 than long, the third is about as long as broad, and those following are longer than broad, 

 becoming half again as long as broad distally. The distal angles of the segments 

 extend slightly beyond the bases of the succeeding segments, this feature increasing in 

 amount distally, and are armed with exceedingly fine spines. The midline of the outer 

 surface of the pinnule is rather broadly roughened and is slightly elevated, forming a 

 roughened band which can scarcely be called a carination. 



P 3 is 5 mm. long with 9 segments; it resembles P 2 and is basally of the same width. 



P! resembles P 3 . 



Notes. The lateral separation of the axillaries and second brachials, the absence 

 of lateral flattening of the division series, and the very small and obscure dorsal processes 

 on the outer cirrus segments give this species superficially much more the appearance 

 of one of the Mariametridae than of a species of Thalassometridae. 



Locality. Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 32; 

 250 meters; sand; April 22, 1922 (1, C. M.). 



PARAMETRA AJAX A. H. Clark 



PLATE 9, FIGURE 29 



Parametra ajax A. H. CLARK, Journ. Linn. Soc. (Zool.), vol. 36, No. 249, April 1929, p. 635 (listed), 

 p. 649 (Malay Archipelago; description), pi. 41, figs. 6, 7. 



Diagnostic features. The arms are evenly rounded dorsally, as in P. fisheri, and 

 the brachials have the distal edge much thickened and produced and armed with very 

 numerous excessively fine teeth; and the cirri are relatively large and stout, XX, 23-27, 

 about one-quarter of the arm length. 



Description. The centrodorsal is thin discoidal with the very broad dorsal pole 

 rather deeply sunken and finely papillose. The cirrus sockets are arranged in one row 

 and a partial second irregular marginal row. 



The cirri are XX, 23-27 (usually nearer the latter), from 20 to 25 mm. in length. 

 The first segment is short and those following gradually increase in length to the fifth 

 or sixth, which is almost or quite as long as broad. The sixth, seventh, or eighth is a 

 transition segment, and is about half again as long as broad. The outer third of the 

 segment is almost white, and the dorsal and ventral profiles of this white portion diverge 

 strongly, the dorsal making a greater angle with the longitudinal axis than the ventral. 

 The segments following decrease in length, after about four becoming about half again 



