HALICHONDBIA. 95 



dissection of Dr. Bowerbank's second volume, yet the 

 laws of nomenclature necessitate that Dercitus must 

 stand. At the same time, in his paper on the arrange- 

 ment of Sponges, as in so many other kindred publica- 

 tions, Dr. Gray has shown that grasp of scientific 

 arrangement and classification which enabled him to 

 detect and lay hold of generic characters ; and I have 

 little doubt that before very long almost all the genera 

 of Sponges which he instituted will be recognised 

 and his names of necessity employed. 



SUB-ORDER III, i, 193 ; n, 8. 



Genus 21. HALICHONDEIA, Fleming, i, 195; n, 9. 



1. HALICHONDEIA MAO!NTOSHII, Bow., in, 340, PI. XCI, 

 figs. 18, 19. 



1874 Halichondria Haclntoshii, Bowerbank. In M'Intosli on 

 the Invertebrate Marine Fauna and Fishes of St. 

 Andrews, Ann. Nat. Hist., ser. 4, vol. xiii, 1874, p. 144 ; 

 and also the Marine Invertebrates and Fishes of 

 St. Andrews, 1S75, p. 15. 



2. HALICHONDRIA EEGULAEIS, Bow., in, 202, PI. LXXIII, 

 figs. 10, 11. 



3. HALICHONDEIA CADUCA, Bow., n, 234; in, 101, PI. 

 XLI, figs. 911. 



1870 Amorphina caduca, Schmidt. Spong. Atlant. Geb., 

 p. 77. 



