BY E. F. KALLMANN. 



653 



Spicules. — (i.) The megascleres 

 are slightly curved cylindrical 

 oxea, styli, strongyla and inter- 

 mediate forms, differing from 

 one another only in the charac- 

 ter of their extremities, and the 

 same in all parts of the sponge; 

 the oxea and styli are present in 

 about equal numbers, while the 

 strongyla are notably fewer. 

 They are of approximately the 

 same dimensions in all the speci- 

 mens examined, ranging in length 

 from about 520/x to slightly 

 above SOO/x, rarely to 850/ji, and 

 varying in maximum stoutness 

 (in different specimens) from 12 

 to 15/x. 



(ii.) The trichites are straight 

 or nearly so, almost immeasur 

 ably fine, and of all lengths be- 

 tween 560 and 620//, and be- 

 tween 60 and 220/;^; the shorter 

 ones are again nearly separable 

 into two groups, individuals be- 

 tween 100 and 150/x in length 

 being very scarce. 



(iii.) The acanthoxea are arcu- 

 ately curved, crescentiform, often 

 very slightly inflated centrally, 

 30 to 45/x in length by 2 to 4/x 

 in stoutness, and densely covered 

 with minute spinules for a dis- 

 tance of from 10 to 15/x from 

 their extremities, the remaining 

 portion of theii- length being smooth 



Text-fig. 

 The curv! 



■* Desmoxya hiiiata. a, megascleres; b, extremities of the .same, more 

 highly magnified; c, spined microxea. 



