BY R. VON LENDENFELD, PH.D. 323 



varieties are not different from one another.) Specimen macerated 

 in fresh water. Magnified 35:1. iH). Radial main fibres with 

 large sand granules in dense masses in the centre. {V). Hyaline 

 tangental connecting fibres free from foreign bodies. 



Fig. 9. — Halme Nidus Vesparum. R. v. L. Surface view of a pore in the 

 outer surface of the' external lamellae with sieve membrane at the 

 commencement of an inhalent canal. Osmic acid-alcohol specimen. 

 Magnified 700:1. 



Fig. 10. — An Oscillaria which is generally found in abundance in the outer 

 surface of the external lamella of Halme species. Drawn after life 

 from a teased portion of the sponge. Magnified 2,000:1. 



Fig. 11. — Halme Nidus Vesparum. R. v. L. Portion of a longitudinal 

 section, showing the ciliated chambers in the dividing membrane. 

 Alcohol-alum carmine specimen. Magnified 8.50:1. {E). Inhalent 

 canals. (A). Exhalent canal. (P). Chamber pores (inhalent). 

 (0). Chamber osculum (exhalent aperture in the chamber wall). 

 (F). A very fine connecting fibre cut through. {S). Stellate tissue 

 cells. (G). Ciliated chambers. 



Plate XXIX. 



Fig. 12. — Halme Nidus Vesparum. R. v. L. Longitudinal section through 

 portion of the finger shaped variety represented in fig. I . Combined 

 picture. Magnified 35:1. (0). An osculum. (P). Pores to the 

 inhalent canals. 



Fig. 13. — Halme Nidus Vesparum. R. v. L. Axial section through a 

 ciliated chamber. Osmic-acid specimen teased out. Combined 

 picture. Magnified 2,000:1. (£"). Inhalent canal. {A). Exhalent 

 canal. (P). Inhalent chamber pores. (0). Exhalent chamber 

 pores. (S). Stellate tissue cells. {d). Flat epithel cells of the 

 canals. 



Plate XXX. 



Fig. 14. — Aulena villosa. R. v. L. A specimen with radial villi and 

 spherical in shape seen from above from a depth of 30 meters 

 Drawn after life. Natural size. 

 Fig. 15. — Aulena villosa. R. v. L. Side view of a specimen with ascending 

 villi of oval shape from a depth of 40 meters. Drawn from life. 

 Natural size. 

 Fig. 16. — Aulena villosa. R. v. L. Surface view of the outer horny 

 membrane covering one of the large sand granules in the skeleton, 

 from a specimen macerated in fresh water. Magnified 1,000:1. 



