6o CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [BuU. 



is most abundant on shelly bottoms in shallow water. In the 

 fall the tide pools in rocky localities along the shore are often 

 crowded with young starfishes measuring from a half-inch to 

 three inches between tips of opposite arms. These are feedmg on 

 the barnacles and young oysters which are attached to the rocks 

 At the approach of winter most of the starfish leave the shore and 

 migrate into deeper water. 



' In spite of the thousands of bushels of these starfishes which 

 are annually destroyed by the oyster growers there seems to be 

 no diminution in their numbers except in restricted localities. 



The size of average mature individuals of this species is from 

 four to six inches between the tips of the opposite arms, but 

 much larger individuals are sometimes found. The variation in 

 the number of rays is discussed on page 43- Th« shape of the 

 rays depends somewhat on the state of contraction of the ambu- 

 lacral groove, and varies with the state of development of the 

 sexual glands and the general nutrition of the body. In general 

 (as shown on Plates II, III, IV, and VIII) they are thick and 

 stout, with blunt and rounded tips. 



Individuals of this species can usually be distinguished from 

 those of Asterias vulgaris by the difference in the proportions of 

 the rays, as shown on Plate VIII. The latter species usually has 

 more slender and pointed rays, while those of the common star- 

 fish are comparatively thick and blunt. 



The coloration of this species is subject to great variation, the . 

 most common shades being greenish or brownish green, with 

 light yellow spines and orange-red madreporic plate. The colors 

 of other specimens range through brown, bronze, orange, and 

 purple. There seems to be little if any correlation between the 

 color of the animal and the age, sex, or environment, although in 



Explanation op Plate VIII. Upper figure, Asterias forbesi. Three- 

 fourths natural size. Lower figure, Asterias vulgaris. One-half 

 natural size. 



Photographs of dried skeletons from oral surface, to show the dif- 

 ferent proportions of thei arms in the two species. The skin, tube-feet 

 and other soft parts have been removed. Around the mouth may be 

 seen in each figure five groups of large spines, the oral spines, or mouth 

 papillae. In the upper specimen the oral spines lie in the positions they 

 occupy when the mouth is closed, while in the other specimen the mouth 

 is fully opened. The ambulacra! grooves are widely opened, and show 

 the four rows of openings for the tube-feet in each groove. (Fronj 

 photographs loaned by Prof. A. E. Verrill.) 



