NEW OPHIURANS OF THE ALLAN HANCOCK 



PACIFIC EXPEDITIOxNS 



(Plates 2-9) 



Fred C. Ziesenhenne 



Research Associate 

 Allan Hancock Foundation 



In the study thus far of the ophiurans, which have been collected on 

 the eight Velero III cruises to the Eastern Tropical Pacific, nineteen ad- 

 ditional new species have been noted, twelve of which were collected on 

 the 1938 cruise when the new dredging apparatus of the Velero III was 

 used. 



It was the writer's good fortune to work with Dr. H. L. Clark, 

 Museum of Comparative Zoolog}^, during the ten weeks of the 1938 

 cruise, and he wishes to express his indebtedness to Dr. Clark for his 

 invaluable advice and opinions and also for certain field and color notes 

 used in the preparation of this paper. 



Thanks are also due to Mr. Anker Petersen, staf? artist of the Allan 

 Hancock Foundation, for the preparation of the illustrations. 



Hemieuryalidae 



Genus SIGSBEIA Lyman 



Sigsbeia laevis, new species 

 Plate 2, Figs. 1-3 



Description. — Disk diameter, 7.5 mm.; arms, about 38 mm. long. 

 Disk small, swollen, and elevated; disk plates swollen, of various sizes, 

 irregularly arranged with no central plate or rosette. Interbrachial scales 

 arranged in 3 rows, a median row of 3 to 5 large, irregular plates sep- 

 arated from the radial shields by a series of small plates. Radial shields 

 triangular, longer than wide, interbrachial margin longest, angles within 

 widely separated by 2 or more large and several smaller disk plates. 

 Between the distal margins of the radial shields and the arm base are 

 7 disk plates arranged in a triangle, transversely to the arm. The disk of 

 the specimen seems to have been crushed at one time, as the radial shields 

 at one arm base have fused into an equilateral triangle with concave sides. 



First upper arm plate oval, twice as wide as long. Succeeding plates 



[9] ^^^^^^ 





