46 ON THE ECHINODERMATA OF THE 



We are still much in ignorance as to the changes undergone by L.furdfer during 

 growth, whilst the records of its occurrence and structure are so few, that we prefer for 

 the present to regard the specimens from Discovery Bay as largely developed examples 

 of the species under notice, rather than to place them as independent forms, from such 

 scanty material. 



Distribution. 



a. Northward up Smith Sound : Discovery Bay, lat. 81 41' N. (Nares's Exped.), 

 the most northern locality on record ; Cape Frazer, 80 fms. 



b. North of American Continent : George's Bank, Gulf of Maine, 150 fms. ( Verrill). 



c. North of European Continent: Bergen, 30-50 fms. (Sars, Dliben and Koren). 



Description of the Illustrations of this Species on Plate III. 



Fig. 9. Abactinal aspect of the animal: natural size. 



10. Actinal aspect of the same specimen : natural size. 



11. Portion near the middle of a ray, actinal aspect: magnified. 



12. Portion near the middle of a ray, abactinal aspect : magnified. 



PTERASTER MILITARIS (0. F. Mutter], M. & T. Plate III, Figs. 13-16. 



1776. Asterias militaris, 0. F. Miiller, Zool. Dan. Prodr. p. 234. no. 2828. 



1788. Asterias militaris, Gmelin, Syst. Nat. Linn. ed. xiii. p. 3100. 



1806. Asterias militaris, Eathke, Zool. Dan. vol. iv. p. 13, tab. 131. 



1842. Asteriscus militaris, Miiller & Troschel, System der Asteriden, p. 44. 



1842. Pteraster militaris, Miiller & Troschel, System der Asteriden, p. 128, tab. vi. fig. 1. 



1844. Pteraster militaris, Diiben & Koren, Kongl. Vet.-Akad. Handl. 1844, jx 246, tab. vii. figs. 11-13. 



1850. Pteraster militaris, Sars, Nyt Mag. f. Naturv. vol. vi. p. 161. 



1853. Pteraster militaris, Stimpson, Invert. Grand Mauan, p. 15. 



1856. Pteraster militaris, Sars, Koren, & Danielssen, Fauna litt. Norv. Heft 2, p. 55, tab. vii. figs. 1-8. 



1857. Pteraster militaris, Liitken, Vid. Meddel. N. Forening i Kjobenhavn, 1857, p. 43. 



1861. Pteraster militaris, Sars, Oversigt af Norges Echinodermer, p. 48. 



1862. Pteraster militaris, Dujardin & Hupe, Hist. Nat. Zooph. Echinoderm.es, p. 434. 

 1866. Pteraster militaris, Verrill, Proceed. Boston Soc. Nat. Hist. vol. x. p. 355. 

 1871. Pteraster militaris, Verrill, Trans. Connect. Acad. A. & S. vol. i. p. 569. 



1875. Pteraster militaris, Perrier, Stellerides du Museum, p. 381 ; Arch. d. Zool. exp. et gen. vol. v. p. 301. 



This Starfish is readily distinguished by the singular fin-like margin surrounding 

 the rays, and by the membranous skin which is supported over the upper surface of 

 the test, as well as by the largely-developed series of webbed spines that resemble fans 

 placed on the adambulacral plates at right angles to the direction of the furrow. 



The contour of the present species is pentagonal, the body being high and arched 

 and the underside flat. Proportion of disk-radius to arm-radius 1 : 2. The ossicles 

 of the abactinal skeleton are subcruciform, and suggest fancifully the idea of a 

 St. Andrew's cross. The major diameter of these plates lies in the direction of the 

 ray, and their prolongations imbricate upon corresponding parts of neighbouring 



