522 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



than l' b . Variation likewise affects the number of arms and the manner of division 

 of the postradial series. There may be IVBr series present, as in the Hamburg 

 specimen (from Port Denison), or these may be entirely absent, as in the Gottingen 

 specimen (from Queensland). 



Hartlaul) Baid it is worthy of remark that this species is in general of a slender 

 habitus, and of a uniform light gray-brown. 



He noted that he had received a specimen from Torres Strait from Dr. P. H. 

 Carpenter for examination. This specimen differed from the others described in 

 having a flatter centrodorsal, the dorsal pole of which is larger and quite flat. Also 

 the cirrus segments are somewhat more elongated. The ossicles of the proximal arm 

 region are somewhat compressed laterally with an angular narrowed dorsal surface, 

 this being more rounded in the other specimens. The color is light yellowish brown, 

 but quite uniform as in the others. The lower pinnules are very fine and delicate, as 

 in the specimen at Gottingen (from Queensland). There are 40 arms, no IVBr 

 series being present. There are prominent keels on the basal segments of the lower 

 pinnules. 



Abnormal specimen. — The specimen presumably from the vicinity of Perth, 

 Western Australia, is one of the most extraordinary comatulids I have ever seen. 

 It has seven radials, which bear a total of 57 arms reaching a length of about 75 mm. 

 The details of the postradial series are as follows, the enumeration beginning with the 

 one just to the left of the anal interradial area and following the hands of the clock 

 around the disk: 



1. A normal postradial series, though a trifle undersized; it bears 8 arms about 

 70 mm. long; all the division series are 2. 



2. Similar to the preceding, but with 6 arms, the two IIIBr series being external; 

 all the division series are 2. 



3. This postradial series arises from a radial displaced ventrally so that in their 

 natural position the arms all he over (ventral to) the arms arising from the radials on 

 either side. The IBr, and IBr 2 are separated by an almost invisible suture. The 

 right branch (as viewed ventrally) bears five arms, the extra axilla^ being on the inner- 

 most side next the left branch. The left branch bears six arms, the left IIBr series 

 bearing two IIIBr series. The 11 arms are slightly smaller than the normal. 



4. A normal postradial series bearing 9 arms. All the IIIBr series are developed. 



5. This postradial series is slightly ventral to the preceding. It bears 10 arms, 

 four on the right and six on the left branch, the extra axillaries on the latter being 

 external. 



6. This postradial series resembles the preceding. It bears nine arms, of which 

 four are on the right branch and five are on the left branch. The extra axillary on the 

 latter is on the side nearest the left branch — i. e., external. 



7. The radial bears four IBr ossicles arranged in two synarthrial pairs — that is, 

 the IBr scries is 4. There is one further division, two IIBr series being present, so 

 that the total number of arms on this postradial series is 4. This IBr 4 series is the 

 only division series not 2. 



The disk hears two anal areas and two anal tubes, the one to the right being 

 slightly the larger. Six of the converging ambulacral furrows are similar and approxi- 

 mately equal, but the postradial series displaced ventrally is supplied by an ambu- 



