70 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



The distal borders of the radials are even with the edge of the centrodorsal. The 

 IBri are exceedingly short and bandlike. The IBr 2 (axillaries) are triangular, twice as 

 broad as long, with the anterior angle sharp, the middle of the posterior margin some- 

 what produced proximally, and the lateral angles extending considerably beyond the 

 anterolateral angles of the IBri. 



The 10 arms are from 30 mm. to 45 mm. long. The first brachial is very short, 

 somewhat shorter interiorly than exteriorly, the two of each arm pair united basally. 

 The second brachial is much larger, irregularly quadrate. The third and fourth 

 brachials together form a syzygial pair somewhat longer interiorly than exteriorly and 

 about twice as broad as the interior length. The following four brachials are approxi- 

 mately oblong, about three times as broad as long, those succeeding soon becoming 

 triangular, about as long as broad, and in the outer part of the arm wedge-shaped 

 and longer than broad. 



Syzygies occur between brachials 3+4, 9+10, and 14 + 15, and distally at inter- 

 vals of 3 muscular articulations. 



P! is small and slender, but somewhat stiffened, tapering evenly and rather rapidly, 

 3.5 mm. long, with 12 segments, most of which are considerably elongated. P 2 is 

 similar, but somewhat smaller and more slender, 2.7 mm. long, with 11 segments. 

 P 3 is from 6 to 7 mm. long, with 18 to 20 segments, slender and almost flagellate. P 4 

 is 4 mm. long, with 13 segments which are shorter than those of P 3 . The following 

 pinnules slowly increase in length, the distal pinnules being from 6 to 7 mm. in length 

 and exceedingly slender. 



Notes [by A.M.C.]. In checking the identity of the British Museum's specimens 

 of Dorometra I found that those from the Maldives named D. nana by Mr. A. H. Clark 

 in 1913 have P 3 much larger and with more numerous segments than any specimens 

 of nana described. 



The largest Maldive specimen has the arm length just over 60 mm. P! and P 2 

 have 10 or 11 segments and measure between 3.5 and 4.5 mm., PI being slightly the 

 longer, while P 3 has 21 to 25 segments and measures 9 or 10 mm. Two other specimens 

 with arm length, respectively, about 50 and 45 mm. have P 3 with 23+ segments, 10 

 mm. long, and 21 segments, 9 mm. long. In D. nana the segments of P 3 have not been 

 recorded as exceeding 16 in number, although specimens with arm length up to 60 

 mm. have been described. The types of mauritiana, with arm length up to 45 mm., 

 have P 3 with 18 to 20 segments. The proportions of the cirrus segments appear to be 

 similar in both species, but the characters of P 3 alone serve to ally these Maldive 

 specimens with the species from Mauritius. 



Localities. Mauritius; on the reef near Port Louis; Capt. Nicholas Pike (A. H. 

 Clark, 1911]. 



Mauritius; Fouquet Island reef; Prof. K. Mobius [A. H. Clark, 1911, 1912; 

 Hartmeyer, 1916] (34, U.S.N.M., 35693; Berl. M., 6376 [type], 6377). Type locality. 



Madagascar; Grandidier, 1905 [A. H. Clark, 1911, 1912] (1, P.M.). 



Hulule, Male, Maldives; S. Gardiner [A. H. Clark, 1913] (5, B.M.). 



History. For some time before I was able to examine any specimens I had been 

 aware of the occurrence of some species of this genus at Mauritius, and indeed in 

 reviewing Mr. Chadwick's paper upon Mr. Grassland's Red Sea collection I mentioned 

 that a species related to D. nana was found there. 



