262 RECENT OPHIURANS. 



755. 0. HEMITELES, sp. nov. (w"-eXiis, half-finished) . Plate 10, f. 7, 8. 



Disk 5 mm. in diameter; arms all broken but evidently long and probably 

 exceeding 40 mm. Disk covered with a coat of rather fine scales, which extend 

 barely to the margin; the interbrachial areas below are covered by naked skin 

 with here and there minute plates carrying, each, a single, low, sharp spinelet; 

 a few of these spinelets may be found just above the margin of the disk. Radial 

 shields about 1 mm. long, and scarcely .5 mm. wide, in contact distally but sepa- 

 rated within. Upper arm-plates, at first somewhat oval and about as long as 

 wide but rapidly becoming elliptical and much wider than long, broadly in con- 

 tact. Oral shields, except madreporite, elliptical, nearly twice as wide as long; 

 madreporite rounded pentagonal, almost as long as broad. Adoral plates rela- 

 tively large, meeting within and also nearly or quite meeting in the mid-radial 

 line; they are 2 or 3 times as long as wide. Oral papillae 2 on each side, small 

 and scale-like; the proximal one is on the oral plate, the distal one on the inner 

 end of the adoral plate. Under arm-plates octagonal with slightly rounded 

 angles, a trifle wider than long, broadly in contact. Side arm-plates low and 

 small; each carries a series of 7 or 8 small, crowded, sharp spines; the third or 

 fourth from the top is longest and equals the joint, the others, especially the 

 lower ones are much smaller. Tentacle-scale 1, large and oval. Color of dried 

 specimen, which has not been in alcohol : — disk skin very dark brown but scales 

 and radial shields nearly white ; proximal ends of radial shields and some marks 

 on disk, dark brown; arms pale reddish buff with every third or fourth upper 

 arm-plate (sometimes two together) dark brown with a light spot at center; 

 oral surface uniformly light. 



HoLOTYPE (M. C. Z. 3739). Torres Strait: Murray Islands, Mer, south- 

 western reef. Oct. 1913. Carnegie Exp. 1913. H. L. Clark coll. 



This specimen had all the appearance in life of an amphim'an and it was 

 a surprise to discover it an Ophiactis. The remarkably long arms, the numer- 

 ous and delicate arm-spines and the large amount of naked skin in the interradial 

 areas, giving an unfinished appearance to the body (hence the name), easily 

 distinguish this species from any Ophiactis hitherto described. 



756. 0. IvROYERI Lutken, 1S56. Vid. med., p. 24, 1859. Add. ad hist. Oph., pt. 2, pi. 3, f. 8a-c. 



184 specimens, including 1 cotype of Ophiolepis atacamensis Phihppi and 

 4 cotypes of Ophiactis fragilis Ljungman. Hawaii: Honolulu. Peru: Payta; 

 Ancon Bay; Callao; Pisco Bay; Paraca Bay. Chile: Atacama, Lsle Blanco; 

 Caldera; Talcahuano. 



