42 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 
Localities —Station 5159; Tawi Tawi group, Jolo (Sulu) Archi- 
pelago; Tinakta Island (N.) bearing N. 82° W., 1.4 miles distant 
(lat. 5°11’50’’ N., long. 119°54’00’’ E.) ; 18 meters; coral sand; Feb- 
ruary 21, 1908. One specimen. 
Station 5164; Tawi Tawi group, Jolo Archipelago; Observation 
Island bearing S. 82° W., 8 miles distant (lat. 5°01’40”’ N., long. 
119°52’20’’ E.); 33 meters; green mud; February 24, 1908. Four 
specimens. 
Remarks.—Although these specimens are only dead tests, without 
the apical systems, the identification as 7’. decipiens is beyond doubt, 
the very characteristic sculpture of the test being quite sufficient for 
the certain recognition of this species. 
That this species has nothing to do with Genocidaris, but is a near 
relation of Temnopleurus reevesii (Gray), will be set forth in vol. 3, 
pt. 2, of my Monograph of the Echinoidea. 
Genus DESMECHINUS H. L. Clark 
DESMECHINUS VERSICOLOR (Mortensen) 
Gymnechinus versicolor MoRTENSEN, The Danish Expedition to Siam 1899-1900, 
II. Echinoidea [Danske Selsk. Skr., ser. 7, vol. 1, No. 1], p. 116, pl. 7, figs. 
24, 26, 30, 1904.—H. L. Crark, Catalogue of the recent sea-urchins in the 
British Museum, p. 129, 1925. 
Locality.—Station 5355; North Balabac Strait; Balabac Light 
bearing S. 61° W., 16.6 miles distant (lat. 8°08’10’’ N., long. 
117°19'15’’ E.) ; 80 meters; coral and sand; January 5, 1909. One 
specimen. 
Remarks.—This specimen, of 20 mm. horizontal diameter and thus 
evidently adult, is rather unusually dark, being olive along the 
median spaces of both ambulacra and interambulacra on the aboral 
side. The spines are greenish but with the usual red bands. 
This species is no Gymmnechinus, but a temnopleurid of the genus 
Desmechinus, as will be explained in vol. 3, pt. 2, of my Monograph of 
the Echinoidea. 
DESMECHINUS RUFUS (Bell) 
Salmacis rufa Bett, Proc. Zool. Soc. London, 1894, 411, pl. 26, figs. 2, 3. 
Psammechinus rufus MorTENSEN, The Danish Expedition to Siam 1899-1900, IT. 
Echinoidea [Danske Selsk. Skr., ser. 7, vol. 1, No. 1], p. 122, pl. 5, fig. 16; 
pl. 7, figs. 34, 48, 1904. 
ie ics rufus H. L. CLrark, Hawaiian and other Pacific Echini, Pedinidae, 
ete., p. 246, 1912. 
Pa th Ae 5179; in the vicinity of Romblon; Romblon 
Light bearing S. 56° E., 4.5 miles distant (lat. 12°38’15’’ N., long. 
122°12’30’’ EK.) ; 68 meters; bottom temperature 24.28° C.; hard sand; 
March 25, 1908. One old broken test. 
