﻿OPIIIONEREIS XANTUSII. 



145 



Disk. Arms, 



0. reticulata 10.;') 70 



0. Xanlusii, 7.7 40 



O.porrecta I'i.O 113 



0. annulata, 11..5 8-1 



Irm-plate. MiJdIe Arm-8plne. 



.7 1.0 



.5 1.2 



1.0 1.7 



.7 2.2 



LIST OF SPECIMENS. 



Whence obtained. 



1038 

 1096 

 1097 

 1200 

 1191 



Maseuin of Comparative Zoology. 



Panama. I I Alex. Agassiz. 



West Coast of Central I University Museum, 



Ameriea. Copenhagen. 



Panama. j Dr. J. LeConte. 



Smithsonian Institution. 



Panama. 

 Panama. 

 Panama. 

 Panama. 

 Cape St. Lucas, Cal. 



Kev. T. PoweU. 



Dr. J. LeConte. 

 J. Xantus. 



Dried. 



Alcoholic. 



Opli 



Ophionereis Xantusii Lthan. 



Xantusil LYM.4JS'. Proceed. Boston Soc. Nat. Hist., VH. p. 2.58. 1860. 



Special Harks. — Brownish straw-color, arms banded with dark 

 purple. Arms about five times as long as the diameter of the disk. 



Description of a Specimen. — Diameter of disk, 7.7""°' ; from outer 

 side of mouth-shield to outer corner of opposite mouth-slit, o""- ; width 

 of arm -^vithout spines, LS""- ; length of arm, 40""° ; distance from outer 

 side of mouth-shield to inner points of inouth-papillfe, to that between 

 outer corners of mouth-slits, 1.2 : 1.5. Mouth-papillae, ten or eleven to 

 each angle of mouth, small, rounded, somewhat flattened. Teeth four, 

 thin, flat, squarish ; lowest one thicker, and with a rounded cutting 

 edge. Mouth-shields much rounded heart-shaped, ^vith narrow end 

 inward ; length to breadth, 1 : .9. Side mouth-shields short triangular, 

 widely separated within. Under arm-plates squarish, a Uttle longer 

 than broad ; outer side slightly curved ; lateral sides a little re-enter- 

 ingly curved ; inner laterals and inner side of about the same length, 

 and lying nearly in the same line ; length to breadth (seventeenth 



