234 H - p - KJERSKOG AGERSBORG. 



temperature, moderate during the entire year, the many sheltered 

 bays and the great abundance of food are undoubtedly contribut- 

 ing factors for the presence of this species of starfish in large 

 numbers. Professor Kincaid, while dredging for marine speci- 

 mens in connection with work at the Puget Sound Marine 

 Station at Friday Harbor, has come to places where he has got 

 the dredge absolutely full of Pycnopodia. 



The coast-lines along the shores of the bays at Bremerton, 

 especially along the shores of the town, are literally covered with 

 starfish of various species. The most numerous is the Evasterias 

 iroschelii (Simpson) ; then, the species Piaster ochraceus (Brandt) ; 

 P. paucispinus and Dermasterias imbricata are also found as well 

 as Pycnopodia. The numeric ratio of the four former is one 

 P. ocraceus to twenty-five E. troschelii; one P. paucispinus to 

 fifty E. Troschelii, and as many Dermasterias as P. ochraceus. 

 There is a considerable variation in the number of rays of E. 

 troschelii. The normal number is of course five, but many have 

 six rays, others seven, and still others four. These species occur 

 in certain belts along the shore, e. g., Evasterias occurs the farthest 

 up; in the lower part of this belt, and extending below, is P. 

 paucispinus. P. ochraceus is seldom found above low-water 

 mark, and together with it are Dermasterias and Pycnopodia. 

 This may then be taken as the upper limit for Pycnopodia, 

 and the lower limit as that as stated before, about fifty fathoms. 

 It is in this respect common with members of the related family 

 Brisingidae (Sars, 1875), e. g., Labidiaster radiosus (Liitken) 

 which, according to Ludwig, occurs in the south Atlantic and 

 south Pacific oceans, in the littoral zone. Verrill, referring to 

 the same species, says: "Unlike the other forms of Brisingidae, it 

 lives in shallow water as well as at considerable depths. It is 

 found on both coasts of Patagonia and off Cape Horn, etc." 



MOVEMENTS. 



Righting Reactions. 



When experimenting on righting reactions care was taken so 

 that the specimens would be under as normal conditions as 

 possible, and no restrictions were put on them. A large number 

 of -trials were made in nature without taking any data; but the 



