206 PROCEEDINOS OF THE NATIONAL MUSEUM. vol.46. 



Papularia small, 2-parted, with about 10 pores, the distal-most 

 being even with a line across the ray between the interradial marginal 

 sutures of either interbrachium. 



Pedicellarise occur abactinally; between superomarginals inter- 

 brachially; intermarginally, on outer part of ray; on actinal inter- 

 mediate plates; irregularly on the inferomarginals. 



Type.— Cat. No. 32627, U.S.N.M. 



Type-locality.— Stsition 5660, Flores Sea (lat. 5° 36' 30" S.; long. 

 120° 49' E.), 692 fathoms, gray mud, sand; bottom temperature, 

 39.2° F. 



Cheiraster Ivdvngi would be placed in Ludmg's table (Notomyota, 

 1910, p. 546) next to Ch. gazellse, from which it differs in having 

 supero-, infero-, and intermarginal pedicellarise, and equal actinal 

 intermediate spinelets (probably not a specific character as it is 

 variable in other species). From Ch. trullipes, ludwigi differs in 

 having a well-developed actinal intermediate area, actinal interme- 

 diate and intermarginal pedicellarise, larger abactinal paxillas, longer 

 furrow spines, 7 oral spines, and 17 (instead of 15) adambulacrals to 

 the first 10 inferomarginals. Oli. trullipes was taken by the Challenger 

 west of Luzon, in 1,050 fathoms, blue mud, bottom temperature 

 37° F. 



This species is named m honor of Dr. Hubert Ludwig, whose paper 

 on the Notomyota furnishes a most useful revision of Cheiraster. 



CHEIRASTER TRIPLACANTHUS, new species. 



Belonging to the subtuberculatus group; differing from suhtuher- 

 culatus in having actinal pedicellarise, 7 or 8 furrow spines, longer 

 inferomargmal spines, and especially in having a transverse series 

 of 3 prominent superomargmal spines on the distal half of ray and 

 1 spme only on the proximal half. Disk large, rays slenderer than 

 in subtuberculatus, tapering very gradually from wide interbrachial 

 arcs to a bluntly-pointed tip. E, = 49 mm., r=12 mm., K, = 4r; 

 breadth of ray at first superomarginal 14 mm., at third, 8.5 mm. 

 No enlarged abactinal spines; papularia large, flat, two-lobed; 

 1 inf eromarginal spine, and proximally 1 or 2 small accessories ; 8 or 

 9 oral, and 1 suboral spine. 



Type.— CeLt. No. 32628, U.S.N.M. 



Type-locality. — Station 5651, Gulf of Boni, Celebes, 700 fathoms, 

 green mud; bottom temperature, 38.7° F. 



The transverse series of 3 prominent spines on the distal marginals 

 is very characteristic and will serve to distinguish the species from 

 Ch. subtuberculatus and Ch. granulatus.^ The presence of only 

 1 prominent int'eromarginal spine and of inf eromarginal pedicellariae 

 are additional differences separating triplacanthus from granulatus. 



> See Ludwig, Notomyota, p. 456. 



