366 A MONOGRAPH OF THE 



3. Chaltna Montaguii, Bowerbank. 



Halichondria Montaguii, Johnston. 



COLUMBvE, Johnston. 



Spongia columbjE. Walker's Essays, p. 196. 



cancellata, Sowerby, Brit. Miscel., 131, pi. lx ; Montagu, in 

 Wern. Mem., ii, 110 ; Turton, Brit. Faun., 208. 

 Scypha cancellata. Gray's Brit. Plants, pi. i, 358. 

 Halichondria columb^;. Fleming's British Animals, 521. 



Sponge. Sessile, irregularly latticed by cylindrical inoscu- 

 lating tubular branches. Surface smooth. Oscula 

 simple, slightly elevated, dispersed, or terminal. Pores 

 inconspicuous. Dermis reticulated, rete uniserial ; 

 dermal membrane aspiculous, pellucid, and thin. 

 Skeleton. Primary lines more or less multispiculous ; 

 secondary lines rarely more than unispiculous ; fibre 

 variable in diameter ; spicula acerate, short and stout. 

 Interstitial membranes spiculous ; tension spicula 

 acerate, slender. 



Colour. Light brown, occasionally pink. 



Habitat. Devonshire coast, Montagu ; Connemara, 

 McColla; Brighton, Mr. Thomas Ingall ; Hastings, J. S. 

 Bowerbank. 



Examined. In the dried state. 



Dr. Johnston's description and figure of Halichondria 

 Montaguii differs considerably from those which have fallen 

 under my own observation ; so much so as to create some 

 doubt whether the sponge he described is identical with the 

 one to which I have allocated that name ; and yet there is 

 so much agreement in the tubular and other parts of the 

 sponge I am describing in its general structure, and no 

 other species known to me which appears to compete with 

 it in right to the name of Montaguii, that I am led to 

 believe that the species in hand is truly the one to which 

 Dr. Fleming applied the name of Montagu. The spicula 

 figured by Dr. Johnston as those of the sponge he describes 

 are certainly very much larger in proportion than those of 



