E. OKIXOSEANA. — SPICULATION. 237 



a rule their one end is outwardly directed, and often freely 

 projects more or less beyond the external surface. 



On several occasions complete graphiocomes have been ob- 

 served with terminals measuring only 'M) fi or 2o /'• in length. 

 These were undoubtedly in immnture stages of their development. 

 PI. VII, fig. 9 represents one such developing graphiucome taken 

 from a young specimen. 



Although the floricome and the graphiocome must be said to 

 belong par excellence to the external trabecular layer, yet certain 

 observations seem to prove that both may sometimes arise in 

 the inner trabecular layer as well. In the latter layer there 

 have at times been found floricoraes apparently young in ap- 

 pearance, and that too under circumstances which made me 

 disinclined to assume that they came there by dislocation. As 

 to the graphiocome, a small and young specimen of the species 

 showed several developmental stages of that hexaster, by the 

 side of the relics of old ones, inside the chamber-layer and close 

 to the gastral surface. 



True oxyhexaders (PI. VIII, figs. 19, 20) occur only occa- 

 sionally and may therefore be easily overlooked unless a special 

 search be made for them. On the other hand, their derivative, 

 the oxystaurader (PI. VIII, figs. 21, 22, oo), is abundantly 

 present in both the outer and the inner trabecular layer, perhaps 

 somewhat more numerously in the former than in the latter. 

 In both kinds of the oxyasters, the diameter usually measures 

 68-100,", exceptionally only about 50,". The smaller sizes refer 

 as a rule to oxystaurasters, while the lai'gest size is found espe- 

 cially among the oxyhexasters. The principals are of moderate 

 length and relatively slender, being about 11," long as measured 



