304 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



(otherwise 12-17 in this species) ; tridentate pedicellariae are usually 

 fairly numerous but sometimes very scarce or even absent (appar- 

 ently otherwise absent in this species) . Possibly these differences 

 will ultimately necessitate distinguishing these specimens as a sep- 

 arate variety (or species?) ; but in view of the great variability of 

 Stereocidaris indica I would think it preferable, for the present at 

 least, simply to consider them as S. indica. 



The specimen from station 5450 is notable through the unusual 

 length of the primaries, up to 82 mm. long in a size of 32 mm. hori- 

 zontal diameter. The color of this specimen also is unusually dark, 

 but this may be due to preservation. One of the specimens from 

 station 5119 is infested with a group of parasitic snails (Stylifer, 

 species?) and has thereby become somewhat deformed. The speci- 

 men from station 5348 is a young one and the identification uncertain ; 

 this also applies to one of the specimens from station 5592. 



STEREOCIDARIS SCEPTRIFEROIDES, var. LAMELLATA, new variety 



Plates 71, 72; plate 74, figs. 8, 9; plate 78, figs. 13, 14 



Locality. — Station 5630; south of Patiente Strait; Doworra 

 Island (N.) bearing N. 3° W., 4.5 miles distant (lat. 0° 56' 30" S., 

 long. 128° 05' 00" E.) ; 1,040 meters; coral sand and mud; December 

 2, 1909 (1 specimen, the type, Cat. No. E. 1286, U.S.N.M.). 



Measurements 



Description. — The test is rather low, distinctly flattened above, 

 slightly less so below, and not sunken toward the peristome. The 

 sides are regularly arched. The circumference is circular. The 

 ambulacra are distinctly sinuate. The interporiferous zone is not 

 much broader than a pore zone. The marginal series of tubercles is 

 very regular, the tubercles not contiguous, usually separated by a 

 pair of small miliary tubercles. Inside the marginal tubercle each 

 plate carries a secondary tubercle about half the size of the marginal 

 one, or even larger, situated at the lower corner of the plate. These 

 secondary tubercles form a pair of very regular longitudinal series 

 within the marginal series, and the whole interporiferous zone is so 

 narrow that it is quite filled up by those four series, no naked median 

 space being left. Rarely there are two smaller inner tubercles instead 

 of the normal one at the lower edge; in such a case a slight irregu- 

 larity is caused in the vertical series. The pores are about equal in 

 size, and are separated by a fairly broad scarcely elevated wall, 

 whereas the ridge separating the pore pairs is rather high, the pores 

 thus being fairly deep lying (pi. 74, figs. 8-9). 



