296 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



fourth small specimen from the same station 13.5 mm. in horizontal 

 diameter has bush-shaped hairs on the primaries, and therefore must 

 be referred to the variety cladothrix. 



Remarks. — These facts seem to show the impossibility of giving 

 this form more than varietal rank, none of the characters of the 

 spines or the test being quite reliable as distinguishing features, and 

 the pedicellariae showing no differences from those of the typical 

 form. The discovery of a specimen of the variety cladothrix, together 

 with the variety rubida, may also perhaps be taken as an indication 

 of the small value to be attached to these varieties. Of course there 

 would be nothing astonishing in getting two distinct varieties in the 

 same haul, but on seeing the specimens together one would be rather 

 inclined to regard them all as identical. 



STYLOCIDARIS ANNULOSA, new species 



Plate 63, fig. 1; plate 64, figs. 1-3; plate 65, fig. 8; plate 75, fig. 3; plate 80, 



figs. 7-11 



Localities. — Station 5278; China Sea, in- the vicinity of southern 

 Luzon; Malavatuan Island (N.) bearing S. 23° E., 8.5 miles distant 

 (lat.l4° 00' 10" N., long. 120° 17' 15" E.); 186 meters; bottom 

 temperature, 15.33° C; fine sand, mud, and shells; July 17, 1908 (2 

 specimens, Cat. No. E. 1328, the type, U.S.N.M.). 



Station 5369; in the vicinity of Marinduque Island; Tayabas 

 Light (outer) bearing N. 50° W., 8.8 miles distant (lat. 13° 48' 00" 

 N., long. 121° 43' 00" E.) ; 194 meters; broken shells; February 24, 

 1909 (9 specimens, Cat. Nos. E. 1268, E. 1327, E. 1329, U.S.N. M.). 



Measurements 



Description. — The test is rather flattened above and below, some- 

 times gently vaulted above. The sides are regularly arched or, in 

 the largest specimen, somewhat more vertical. The circumference is 

 circular, in the largest specimen slightly subpentagonal. 



The ambulacra are rather distinctly sinuate. The interporiferous 

 zone is about twice the width of a pore zone. The marginal series of 

 tubercles is perfectly regular; the tubercles are small and incon- 

 spicuous, nearly contiguous. Within the marginal tubercle each 

 plate carries a single, much smaller, tubercle at the lower edge, the rest 



