148 



OPIIIONEREIS PORRECTA. 



Ophionereis porrecta. (Lower side.) 



d, mouth -papillae ; c, inner point of mouth angle ; 



q, tentacle-scale. 



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

 under 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 light-colored 



joint ; arm-spines pale brown, with one 

 or two darker rings ; underneath inter- 

 brachial 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 Ijrown. 



Variations. — A young one, with a 

 disk o""^- in diameter, had arms 18'°'°- 

 long. The disk-scales were large, about 

 40 to a square mm., and among them 

 could plainly be recognized the primary 

 plates ; the radial shields were conspicuous, 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-shaped, with an angle within, and a wide, straight 

 outer side, and were entu^ely separated by the encroachment of the 

 side arm-plates. The other parts were as in the adult, 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 arjus, the shortness of the arm-spines, and the 

 general robustness of the structure. 



LIST OF SPECIMENS, 



Catalogue Original j Number 

 Number. Number. ; of Spec. 



Locality. 



When 

 Collected. 



Whence obtained. 



Nature of 

 Specimen. 



11 



Museum of Comparative Zoology. 

 7 I Florida ? ! ! 



Alcoholic. 



