596 PROCEEDINGS OP THE ACADEMY OP [Aug., 



VAKIABILITY AND AUTOTOMY OF PHATARIA. 



BY SARAH P. MONKS. 



Phataria (Linckia) unifascialis Gray, var. hifascialis is a starfish 

 that is remarkable for the variabihty in the size and number of its 

 rays. Regularity is the exception. In over 400 specimens examined 

 not more than four were symmetrical and no two were alike. Fig. 

 13, PI. XLII, is a nearly symmetrical six-raj^ed star, but one of its 

 rays has been broken off and renewed. 



The plate shows the great variability in size of stars, number of rays 

 and different breaking places. 



The animals vary in size from four to seventeen centimeters. This 

 difference may in some measure be due to age. but there is evidently 

 also considerable difference in size in adult specimens. 



The normal number of rays is five, but some specimens have onl\^ 

 one, while others have four, six, seven, or even nine; four, five or six 

 being most common numbers. Of 248 specimens examined 29 had 

 one ray, 34 four rays, 135 five rays, 44 six rays, 5 seven rays and 1 

 nine raj^s. 



There is a marked irregularity in the size of the rays, for the breaking 

 and renewing occur at all ages, or, at least, at all sizes. Single 

 living rays without any externa! sign of disk are not micuinnion. 

 Twenty-two in a lot of 240 were single. In animals measured the rays 

 varied in length fi'om 22 75 mm., and wei-e in all conditions, from speci- 

 mens which sht)wed by tlie raw siu'face tiiat the l^reakage was recent, 

 through all grades of healing surfaces to stars where new rays appeared 

 as mere buds, to the comet series and to the \'arious rays of adnlt 

 Phataria'. 



Comets are fiv(iuently found; tlicic were foi'ty-oneof tiiein in 240 

 specimens. These are stars with one long I'uy and a nuniln'r of small 

 rays extending from a minute disk. 'J'iiey aw rays that ha\'e made a 

 new body. In PI. XITI, 3-11 are. comets. The long ray is from 

 2-7 cent, in length. ( )n account of their small size the single rays and 

 comets are more easily overlooked by collectors. 



This species of Phataria is mottled reddish-brown and ash color, with 

 the tips of the I'ays and the small new raj's, or new })ortioii of the ray, 



