494 DR. J. E. GRAY ON SPONGES. [May 9, 



pronged or three-hooked elongate spicules are characteristic of the 

 Geodiadce and Tethyadce. 



The anchorate and birotulate spicules and other forms of the series 

 are almost peculiar to the family EsperiadcB. 



The six-rayed stars, often divided at the ends, are peculiar to the 

 EuplectellidcB and Dactylocalycidce. 



The four-rayed stars, with elongate simple rays, to the Carteria. 



Dr. Bowerbank has described and figured a large number of the 

 forms of spicules, and the manner in ■which they are arranged in the 

 different families and genera, in the ' Philosophical Transactions ' for 

 1858, p. 2/4, and 1862, p. 747. The whole of these plates have 

 been rather coarsely copied in his * Monograph of the British Spon- 

 giadse,' published by the Ray Society for 1864. And Prof. Oscar 

 Schmidt has also given some excellent figures of the spicules in his 

 work on the 'Adriatic Sponges,' and the two Supplements to that 

 work, 1862 and 1866. 



Various systems for arranging sponges have been proposed. The 

 following are the most important : — 



M. Ducrotay de Blainville, in his ' Manuel d'Actinologie ou de 

 Zoophytologie,' 8vo, 1834, forms the sponges into a group he calls 



Les Amorphozoaires {Amorphozoa), containing the genera: — 



1. Alcyoncellum (Alcyoncella in index). 2. Spongia. 3. Calci- 

 spongia. 4. Halispongia, 5. Spongilla. 6. Geodia. 7. Ccelop- 

 tychium. 8. Siphonia, 9. Myrtnecium. 10. Scyphia. II. Uudea. 

 12. Haliirhoa. 13. Hippalimus. 14. Cnemidium. 15. Lym- 

 norea. 16. Chenendopora. 17. Tragos. 18. Mamon. 19. Icrea. 

 20. Tethium. 



The names in italics have only been found in the fresh state. 

 He places Cliona of Dr. Grant with the Zoophytaires sarcinoides, 

 or Alcyonaires {Alcyonaria). 



G. D. Nardo has published "Auszug aus einem neuen System 

 der Spongiarien (Spongiariorum Classificatio) " in the ' Isis,' 1833, 

 p. 520, and " De Spongiis," ' Isis,' 1832, p. 714, in which he divides 

 sponges into three orders : — 



I. Spongiaria fulcimentis natura cornea. 

 1. Spongia. 2. Ixcima. {^Sp. cavernosa, 'Lmn.l). 3. Aplysia. 



II. Spongiaria fulcimentis natura silicea, aculeiformibus aut granu- 

 losis et substantice animalis ope vario modo coalitis. 



1. Grantia {Sp. canabina, Esper ; Sp. lamia, Sp. damicornis, 

 and Sp. lactuca, Esper, not Johnst.). 2. Raspalia {Sp. dichotoma. 

 Link). 3. Donatia (*S^. lyncurium, Sp. cydonium). 4. Rayneria. 

 5. Esperia. 6. ^Vihevite^ {Ale. domuncula ?indi A. Jicus). 7. Lita- 

 mena. 



III. Spongiaria fulcimentis natura calcarea, etc. 



1. '&irdiX\^\2i^ Alcyonium arbor eum, lAnn. 2. Yioa. = A ley onium 

 asbestinum, Linn. 



