130 ECHINODERMS OF THE BRITISH ISLES 



Of the genus Coronaster two species are known from the East 

 Atlantic ; viz. Coronaster Parfaiti E, Perrier (off Cape Verde 

 Isl., 150 m.) and C. Antonii E. Perrier (Bay of Biscay, off Cape 

 Spartel, Morocco ; ca. 400-700 m,). The two species are thus 

 distinguished : 



Kays 1 1 ; the five inner adainbulacrals with 3 spines in a transverse 

 series ; wreath of pedicellarise high up on the spines 



C. Parfaiti Perrier 

 Rays 9 ; all adambulacrals with 2 spines, the one somewhat 

 behind the other, sometimes almost forming one longitudinal 

 series. Wreath of pedicel! ariae at the base of the spines 



C. Antonii Perrier 



The position of the wreath, at the base or higher up on the 

 spine, is scarcely a reliable difference ; the position at the base 

 of the spine may rather be due to preservation, as is the case in 

 some of the Asteriidae. 



The species of this genus are splendid sea-stars, somewhat 

 recalling Solaster, and may reach a considerable size (R.= 190 

 mm. in C. Antonii). 



Of the genus Pedicellaster two species are know^n from the 

 Atlantic, viz. Pedicellaster typicus M. Sars (Scandinavia, from 

 60° N. to Spitzbergen and the Kara Sea, and from West Greenland 

 to 42° N. on the American coast ; ca. 20-1130 m.), and P. sex- 

 radiatus E. Perrier (Bay of Biscay to Cape Verde and the Azores ; 

 ca. 600-3465 m.). The two species are thus distinguished : 



Rays 5 ; spines of dorsal side distinctly smaller than the adambu- 

 lacral spines ; no series of spines along the adambulacrals 



P. typicus M. Sars 



Rays C ; spines of dorsal side fairly long and slender, as long as the 

 adambulacral spines. A series of spines parallel to the adambu- 

 lacrals, giving the appearance that there are 3 spines in each 

 transverse series . . . .P. sexradiatus E. Perrier 



They are small forms, scarcely exceeding 40 mm. length of 

 arms, very much resembling young specimens of Asterias. 



While P. typicus has large eggs and, therefore, probably direct 

 development, without a pelagic Bipinnaria stage, P. sexradiatus 

 has numerous small eggs and may be expected to have a typical 

 pelagic larva. In fact, there is much reason for assuming that 

 the so-called " Stellosphcera mirabilis " Koehler and Vaney (which 

 is only a Brachiolaria in metamorphosis) really is the larva of 

 Pedicellaster sexradiatus ; this probably also holds good for the 

 Brachiolaria liihernica Gemmill, which appears to be identical 



