﻿OPIIIURA JANUARIl. 



25 



mouth-shields, such as are found in Ophiarachna. It would seem that 

 this sjDecies has variations similar to those of O. longicauda. 



LIST OF SPECIMENS. 



Whence obtained. 



100 

 101 

 102 

 ?103 

 444 



Museum of Comparatice Zooli 



Now B.vUnr.l, :\Iass. 



Du-tiimiiUi. 



S:..r lliu-lior, L. L •? 



Beaufort, N. C. 



Beaufort, N. C. 



Jlay, 



Sinilhsonian Institution. 



1 I 01(1 Point Comfort, Va. I 



12-(- Beaufort, N. C. 



Prof. Agassiz. 

 Prof. Agassiz. 

 Dr. Ayres ? 

 Win. Stinipson. 

 A- S. Bickmore. 



Wm. Stinipsun. 



Alcoliolic 



Dried. 



Alcoholic 



Ophiura Januarii Lyman. 



Opliioderma Januarii Lutken. Vidensk. Meddelelser. Jan., 1856. 

 Ophioderma Januarii Lutkex. Addit. ad Hist. Opb., p. 97. 



Sjjecial 3Iarks. — Arm-spines nearly as long as joints, round, slender ; 

 arms tapering, slender. Color, variegated greenish-gray, above ; below, 

 lio-ht straw-color. Side mouth-shields naked. 



Descrii^tion of a SjJecimen. — Diameter of disk, 17"""'; from outer side 

 of mouth-shield to outer corner of opposite mouth-slit, 7.2"'"- ; width of 

 arm, without spines, 3.5""°" ; length of arm, 82°'"'- ; distance from outer 

 side of mouth-shield to inner point of teeth, to that between outer cor- 

 ners of mouth-slits, 4 : 4. Mouth-papilla? sixteen to eighteen, of more 

 even size than usual ; second and third flat, squarish, with rounded 

 edges ; the rest rounded, spiniform, nearly equal. Teeth five ; upper- 

 most and lowest flat and tapering, the former longer ; other three flat 

 and square. Mouth-shields short heart-shaped ; length to breadth about 

 1.7 : 2. Side mouth-shields broad, rather conspicuous, naked. Under 

 arm-plates, near base of arm, broad octagonal, with four outer corners 

 more or less rounded ; length to breadth (eighth plate), 1 : 1.5 ; (twelfth 

 plate), 1 : 1.3. First plate nearly oval, proportionately larger than 

 usual ; length to breadth, .8 : 1.3. About two thirds out on arm, the 

 plates become nearly hexagonal, owing to encroachment of side arm- 

 plates, which may be seen very plainly, both from above and from 

 below. Upper arm-plates broader than long, bounded within and with- 

 out by straight lines ; inner side shorter ; outer corners well rounded ; 

 three or four plates enclosed by projections from disk, and modified in 



