7G0 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



and fifth are about half again as long as broad and more slender than those preceding, 

 and those following become rapidly elongated with swollen articulations so that the 

 pinnule is ver}' slender and filiform distally. P2 is very slightly shorter with the first 

 segment broader than long, the second about as long as broad, the third about half 

 again as long as broad, and the remainder becoming progressively elongated. This 

 pinnule is about as stout basally as Pi but does not taper so rapidly, so that it appears 

 considerably stouter; a large gonad occupies the fourth to eleventh segments. The 

 follo\ving pinnules, so far as they are preserved, resemble Po. 



Notes [by A.M.C.]. — In the largest syntype of T. cypris the centrodorsal is similar 

 to that of the type of parva, but there are XXXV-XL cutus sockets and the remaining 

 cirri have up to 13 segments, which appear to be similar in proportions to those described 

 above. The arms were about 30 mm. long and the length from I Br, to the second 

 syzygy is 6.5 mm. The breadth of the arm at the first syzygy is 0.8 mm. 



The longest remaining P, has 15 segments and measures 5.5 mm., probably three 

 or foiu" segments are lacldng. Po is stouter and probably shorter but all are broken; 

 in most cases it carries a small gonad. On the succeeding pinnules the segments be- 

 come progressively more attenuate. 



The two remaining syntypes of cypris are smaller. One has the length IBrj to the 

 second syzygy 5 mm. The other is still smaller and has no gonads. They have respec- 

 tively up to 11 and up to 9 cirrus segments which are relatively longer than in the 

 larger specimen and which have more prominent opposing spines. 



In 1922 Dr. Toi-sten Gislen recorded a specimen from Sagami Bay in 731 meters 

 which he named Thaumatomfitm comaster. In the typescript Mr. Clark had referred 

 this to T. isis but the reexamination of the types of cypris has revealed even greater 

 similarities, notably the fact that in both Gislen's specimen and in the largest type 

 of cypris, as in the type of parva, P2 is the first genital pinnide. The relatively shorter 

 cirrus and pinnule segments in Gislen's specimen are probably attributable to its larger 

 size, the arm length being about 45 to 50 mm. The centrodorsal is very low conical, 

 2 mm. broad at the base and 0.6 mm. high, the bare dorsal pole measures 1.1 mm. 

 in diameter. 



The cirri are about XXXV, 12-15, from 7 to 8 mm. long, arranged in two rows on 

 the centrodorsal. The first cirrus segment is short, the second is about as long as 

 broad, the third is twice as long as broad, the fourth to sixth are three times as long 

 as broad, the seventh is two and a half times as long as broad, and the antepenultimate 

 is very slightly longer than broad. The terminal claw is about as long as the penulti- 

 mate segment. 



The IBr, are three or fom* times as broad as long laterally. The axillaries are as 

 long as broad, produced both proximally and distally, the proximal projection being 

 longer than the distal. The lateral angles are produced beyond the anterolateral angles 

 of the IBr,. 



The 10 arms are between 45 and 50 mm. in length. The first brachials are three 

 times as long exteriorly as interiorly and interiorly in contact basallj''. The second 

 brachials have a strong posterior process. The fu'st syzygial pair (composed of the 

 third and fourth brachials) is a little longer interiorly than exteriorly. Tlie following 

 brachials are about as long as broad, slightly wedge-shaped. The distal brachials are 

 somewhat longer than broad with swollen articulations. 



