1908.^ SPICULES OF CALCAREOUS SPONGES. 675 



Grant, R. E. — " Remarks on the Structure of some Calcareous 



Sponges." Edinburgh New Philosoiahical Journal, i. (1826) 



pp. 166-170. 

 Haeckel, E. — Die Kalkschwamme. Bel. I. Berlin, 1872, pp. xvi + 



484. 

 Kolliker, a. — Icones Histiologica?. Erste Abtheilung. Leipzig, 



1864. 

 Lendenfeld, R. v. — " The Histology and Nervous System of the 



Calcareous Sponges." Proc. Linn. Soc. N. S. Wales (1) ix. 



(1885) pp. 977-983. 



" Die Spongien der Adria. — 1. Die Kalkschwiimme." 



Zeitschr. f . wiss. Zool, liii. (1891) jop. 185-321, & pp. 361-433, 

 pis. viii.-xv,, 1 text-fig. 



LiEBERKtJHN, IST. — " Beitrage zur Anatomie der Kalkspongien." 



Arch. f. Anat. Physiol, und wiss. Med. 1865, pp. 732-748, 



pi. xix. 

 Maas, 0. — " TJeber den Aufbau des Kalkskeletts der Spongien 



in normalem und in CaCo^-freiem Seewasser." Yer. Deutsch. 



Zool. Ges. 1904, pp. 190-199. 

 Minchin, E. a. — " Materials for a Monograph of the Ascons. — 



I." Quart. Journ. Micr. Sci. n. s, xl. (1898) pp. 469-587, 



pis. xxxviii.-xlii. 



Article " Sponges," in Lankester, A Treatise on Zoology, 



part ii. London, 1900. 



" Materials for a Monograph of the Ascons. — II." Quart. 



Journ. Micr. Sci. n. s. lii. (1908) pp. 301-355, pis. xvii.-xxi., 

 5 text-figs. 



Schmidt, 0. — Die Spongien des Adriatischen Meeres. Leipzig 

 (W. Engelmann), 1862. 



Weinschenk, E. — "IJeber die Skeletteile der Kalkschwamme." 

 Centrbl. Mineral. Geol. Palaontol. 1905, no. 19, pp. 581-588. 



"Woodland, W. — " Studies in Spicule Formation. — I. The Devel- 

 opment and Structure of the Spicules in Sycons ; with 

 Remarks on the Conformation, Modes of Disposition and 

 Evolution of Spicules in Calcareous Sponges generally." 

 Quart. Journ. Micr. Sci. n. s. xlix. (1905) pp. 231-282, 

 pis. xiii.-xv., text-figs. 1-11. 



EXPLANATION OF THE PLATES. 



All the photographs are from spicules stuck on the slide with albumen, decalcified 

 and stained with picro-nigrosin, and mounted in Canada balsam. 



Pigs. 1-10. Clathrina contorta. 

 Fig. 1, PI. XXXIV. A triradiate. X 400. 



2, PI. XXXV. The central portion of another triradiate. X 1000. 



3, PI. XXXIV. A quadriradiate, gastral aspect. X 400. 



4, PI. XXXV. A quadru-adiate, gastral aspect, at a high focus to show the 



gastral raj- in optical transverse section. X 1000. 



5, PL XXXV. The central part of a quadriradiate. X 1000. 



6, PI. XXXV. The central part of another quadriradiate. X 1000. 



7, PL XXXV. The central part of another quadriradiate. X 1000. 



8, PI. XXXVII. The extremity of a ray of a quadriradiate. X 1000. 



9, PL XXXV. A small-sized monaxon. X 150. 

 10, PL XXXV. Another small monaxon. X 150. 



