METALIA STERNALIS. 209 



detail by Mortensen (1913. Mitt. Zool. Stat. Neapel, 21, p. 32-34, pi. 3). To 

 judge from the photographs the form of the test is much more like that found 

 in Metalia than like that of P. grandis. 



Metalia. 



Gray, 1855. Cat. Rec. Ech. Brit. Mus., p. 51. 

 Type, Spatangus sternalis Lamarck, 1816. Anim. s. Vert., 3, p. 31. 



As the pediceilariae of this genus have scarcely been examined hitherto, I 

 have given particular attention to them. They show little diversity as neither 

 ophicephalous nor globiferous were found, nor did I see any which could be 

 called triphyllous. The rostrate are present in some numbers and tridentate 

 in various forms are abundant, but I fail to find any generic characters in 

 either. Careful reading of Bell's description shows no reason for recognizing his 

 proposed genus Eobrissus; it seems better to put the new species in Metalia. 



Key to the Species of Metalia. 



Apical system distinctly anterior. 



Petals I and V more or less confluent; no primary tubercles at dorsal proximal 



end of interambulacrum 5 sternalis. 



Petals I and V not at all confluent; primary tubercles present at dorsal proximal 

 end of interambulacrum 5. 

 V. d. less than ^ test-length; apex .33-40 test-length from anterior margin; 



sternum with a single median point where it meets subanal fasciole . . . spatagus. 

 V. d. more than § test-length; apex less than .30 test-length from anterior 

 margin; sternum with 2 points (3-5 mm. apart) where it meets subanal 



fasciole dicrana. 



Apical system subcentral townsendi. 



Metalia sternalis. 



Spatangus sternalis Lamarck, 1816. Anin. s. Vert., 3, p. 31. 



Brissus (Metalia) sternalis Gray, 1855. Cat. Rec. Ech. Brit. Mus., p. 51. 



Plate 146, fig. SO. 



From Zanzibar to the Hawaiian and Society Islands is the range of this 

 well-known species. It is one of the most diversiform of spatangoids and 

 its growth-changes are very remarkable. Only the examination of many speci- 

 mens can convince one that the younger individuals are really the same species 

 as the full-grown adults. Mr. Agassiz called attention to this matter in the 



