﻿148 



OPHIONEREIS PORRECTA. 



third joint), 1, 1.7, 1.3 : 1. Tentacle-scale oval, large ; length to that of 

 tinder arm-plate, .6 : 1. Color, in alcohol : above, disk minutely mottled 

 and lined with reddish brown (vandyke brown and red chalk) and dirty 

 white ; arms the same, but darker, with occasionally a lightrcolored 

 joint ; arm-spines pale brown, with one 

 or two darker rings ; underneath inter- 

 ])rachial spaces tawny brown ; darker 

 along the genital slits ; mouth-parts and 

 under arm-plates white ; the arm-plates 

 and mouth-shields with a few specks of 

 various tints of brown. 



Variations. — A young one, with a 

 disk S""' in diameter, had arms 18°"°' 

 long. The disk-scales were large, about 

 40 to a square vim., and among them 

 could plainly be recognized the pi'imary 

 plates ; the radial shields were consjjicuous, though small, and were 

 separated by a wedge of two or three scales ; the upper arm-plates 

 were very nearly circular, and overlapped each other ; the lower arm- 

 plates were shield-sha2Ded, with an angle within, and a wide, straight 

 outer side, and were entirely separated by the encroachment of the 

 side arm-plates. The other parts were as in the ackilt, except that the 

 side mouth-shields were proportionately larger. In a specimen with a 

 disk of 5""°-, the upper arm-plates were shaped nearly as in the adult ; 

 the under arm-plates were tawny red. Among the young the radial 

 shields were commonly bordered with dark brown, with a white centre. 

 The other colors varied chiefly in intensity. 



The locality of these specimens has unfortunately been lost ; but 

 they are believed to be from the Atlantic coast of America, and are 

 therefore included here. The species is distinguished from others by 

 the great length of the arms, the shortness of the arm-spines, and the 

 general robustness of the structure. 



LIST OF SPECIMENS. 



Whence obtained. 



Muse7im of Comparative Zoology, 

 11 I . . ] 7 I Florida? 1 I 



