380 Mr. R. Kirkpatrick on the 



We have, therefore, in the life-history of Myzontoma, as 



detailed by Wheeler, a remarkable confirmation of Smith's 

 theory of secondary hermaphroditism, and a further case in 

 which it appears to supply a complete interpretation of facts 

 hitherto lacking an explanation. 



Literature. 



1894. Beard, J. — Zool. Anzeiger, xvii. 



1898. . Mittheil. Stat. Neapel, 1893-1899. 



1909. Orton, J. H.— Proc. Royal Soc, B, vol. 81. 

 1906. Smith, 6. W. — Naples Sfonogr. xxix. 

 1894. Wheeler, W. M. — Zool. Anzeiger, xvii. 

 1896. . Mittheil. Stat. Neapel, 1896-1897. 



LV.— On the Affinities of Astrosclera willeyana, Lister. 

 By R. Kirkpatrick. 



(Published by permission of the Trustees of the British Museum.) 

 [Plate XL] 



AMONG some sponges collected by Dr. C. W. Andrews, 

 F.R.S., off Christmas Island, and presented to the Natural 

 History Museum by Sir John Murray, were four small 

 examples of Astrosclera willeyana, Lister. The specimens 

 had been detached from a block of coral rock brought up 

 from a depth of 46 fathoms, and had been put into alcohol. 

 The largest example, which is mushroom-shaped, is 12 mm. 

 high, 8 mm. in diameter at the base of the round stem, and 

 14 mm. in diameter across the convex head. The rounded 

 upper surface is smooth and shows a reticulate pattern with 

 irregularly meandrine or rounded meshes about a millimetre in 

 diameter. Several stellate oscular areas are scattered over 

 the surface. In a vertical section of the sponge the strand-5 

 of the network are seen to be the edges of walls or lamella? 

 composed of loosely aggregated spherules, which amalgamate 

 lower down to form solid masses. 



A second columnar specimen, 12 mm. high, was decalcified 

 and stained. A third example formed a small cylindrical 

 nodule, and a fourth an irregular disk 7 mm. in diameter and 

 2-3 mm. thick. 



Vertical longitudinal sections of the decalcified specimen 

 showed a tubular network with numerous elongated longitu- 

 dinal strands hanging down from a surface layer (of ecto- 

 some), and joined by fewer and shorter more or less transverse 

 tubular bars. 



