356 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



line joining its lateral angles, and more of the IBr, is visible. Similarly the second 

 brachial projects backward less strongly uito tlie first, and the arm bases as a whole are 

 less tubercular. 



Willfm Barents station 21, 18S1: In the 10 specimens obtained here some of the 

 axillaries are distinctly triangular, while others are as distinctly diamond-shaped, and 

 there is more or less variation in form between the five axillaries of each individual. 

 A similar indefiniteness prevails in the relative proportions of the lower pinnules, for 

 both P3 and P, may be much smaller than Po, and more nearly equal than they are in 

 the two large specimens from Stas. 17 and 18, while the basal segments of these lower 

 pinnules have their distal ends considerably raised above the pro.ximal ends of the 

 following segments. 



Witlem Barents station 21, 1880: The 9 specimens obtained here are somewhat 

 less mature than those dredged in 1881, and the arm bases are less tubercular, with 

 relatively longer segments. Portions of the radials are visible in the angles of the 

 calyx, as well as the whole of the trapezoidal IBri, which are much raised in the center 

 and deeply incised to receive the strong posterior process from the middle of the base 

 of the axillary. 



Jan Mayen, 140-300 meters: In small specimens with arms from 40 to 60 ram. 

 long the cirri have 20 to 28 segments. At the ends of the arms the two basal pinnule, 

 segments which, in the fully grown are flattened and larger than those following, in the 

 young appear rounded. 



Jan Mayen, 150 meters, Pourquoi Pas? station 2041: Remy (1928) comments that 

 Mortensen's figiu-e (Medd. Gr0nl., 1900) of the tip of an ovigerous pinnule is inexact, 

 showing the terminal segment as too long, the division between the last two segments 

 probably having been omitted. Remy found that both specimens from Jan Mayen 

 and the Challenger specimens examined by him have the last segment of the ovigerous 

 piimulcs almost twice as short as the preceding segment and with the fonn of a hook 

 terminated by a few strong spines. 



A number of specimens of arm length less than 100 mm. have been recorded with 

 some development of ornamentation on the proximal ossicles. Eight specimens from 

 Seydisfjord, Iceland, have the arms between 45 and 70 mm. in length; the smaller 

 have the elements of the division series and the first two brachials spinous but the 

 larger ones are almost entirely smooth. In one from Ingolf station 15, with arms only 

 26 mm. long, these same ossicles bear long spines on their borders. Other such speci- 

 mens include one from Camp Clay, Cape Sabine, with cirri 1,3 mm. long, another from 

 Tasiusak Fjord with arms 65 mm. long and others from the Kara Sea with arms 30 to 

 50 mm. long. Some specimens show a trace of median carination, at least on the 

 division series, notabl}^ from Alexander Kovalevsky station 70, with arms 80 mm. long, 

 station 58 witii arms 40 mm. long, and station 56 with arms 30 mm. long. 



Differences in the proportions of the pro.ximal pinnules of different arms of the 

 same individual have been observed. One from Yermak station 28, with arms 00 mm. 

 long has on four different arms Pj 14.5 mm., 14 mm., 13 mm., and 14 mm. long with 37, 

 32, 28 and 34 segments respectively and P3 8 or 9 mm., with 17 or 20 segments. 



In general, larger specimens tend to have more of the proximal pinnules elongated 

 and similar to Pi than do small specimens. At an arm length of 50 to 100 mm., only 

 Pi and P2 are much elongated, P3 being abruptly smaller, but when the arms are over 

 200 mm. long the pinnules as far as P5 or Pj may be very long. 



