84 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



The animals have remarkable powers of regeneration, for 

 they have the habit of throwing off the disk when violently dis- 

 turbed, leaving only the mouth frame and adhering organs at- 

 tached to the arms. Under favorable conditions they are able 

 to regenerate the missing disk, and specimens have been collected 

 in which such regeneration was actually in progress. 



Full details of the anatomical peculiarities are given in Ver- 

 rill's original description of the species.* 



The species is also fully described in Verrill and Smith's 

 Invertebrate Animals of Vineyard Sound, page 426, although the 

 description there given has been revised in certain details in a 

 later paper by Verrill. f 



Amphioplus macilentus Verrill 

 Plate XIX, fig. 2. 



This species is closely related to the preceding, but is dis- 

 tinguished by having five oral papillae in each row, and the spines 

 at the sides of the arms are all slender. 



Although this species has not yet been recorded from Long 

 Island Sound, it has been collected at various localities so near 

 the eastern entrance to the Sound as to render it highly probable 

 that further investigation will reveal its presence in Connecticut 

 waters. It has been dredged by the United States Fish Com- 

 mission in muddy localities at numerous stations off the south- 

 eastern coast of New England, and in certain places occurs in 

 large numbers as far south as Cape Hatteras. 



Full details of the anatomical peculiarities are given in Ver- 

 rill's original description of the species.$ 



The individuals belonging to this species are small, with 

 very long and slender arms (Plate XIX, fig. 2). The disk is 



* Am. Journ. Sci., 3rd series, vol. ii, p. 132, 1871. 



t North American Ophiuroidea. Trans. Conn. Acad., vol. x, p. 314. 



$ Am. Journ. Sci., 3rd series, vol. xxiii, p. 142, 1882. 



EXPLANATION OF PLATE XIX. 



Fig. i. Amphioplus abditus. Oral surface of disk and portions of rays. 

 One of the extremely slender rays is in process of regenera- 

 tion. Three times natural size. 



Fig. 2. Amphioplus macilentus. Oral and aboral surfaces, showing the 

 extreme slenderness of the rays. Twice natural size. 



