I2 6 PORIFERA. H. 



between their ends, and the more they approach the monactinal form. This rule seems to be a gener- 

 al one; it is to be noted, however, that in the new genus Dendoricella established below, the dermal 

 spicules are really diactinal. I have not yet been able to decide, whether these features may get any 

 systematic importance. 



It is, accordingly, to be remembered that when in the following the dermal spicules in diag- 

 nosis and description are called diactinal, this term is a purely descriptive one and means only that in 

 their final form the spicules are more or less equi-ended. 



Dendoricella n. g. 



(Damiria Topsent). 



The form massive, lobate or erect, club-shaped. The skeleton polyspicular, irregular or dendritic; 

 the dermal skeleton consists of more or less erect bundles of dermal spicules. Spongin present or wanting, 

 Spicula: Megasclera : the skeletal spicules diactinal. oxea (or strongyla). the dermal spicules oxea. tornota. 

 or tylota ; microsclera chc.hr arcuatcr solely, or chela" arena fir and sigmata. 



Topsent (Archiv de Zool. exp. et gen. Ser. 2, X, XXI) mentions the genus Damiria Keller, 

 and characterizes it as being distinguished from Dendoryx (in Topsent's sense) by its diactinal 

 skeletal spicules. Later has for instance Lindgren followed Topsent in this view. Weltner, 

 however, (Zool. Anzeig. XXI, 1898, 429) has shown that Damiria Keller has by its author been correctly 

 referred to the Renierids, and has nothing to do with the Myxillae, and after having examined a frag- 

 ment of the type specimen kindly sent me by Dr. Weltner I can only corroborate this view. For 

 the generic conception which Topsent in the quoted place calls Damiria we must thus have a new 

 name. Ridley has referred a species belonging here to the genus Crella Gray (Cribrella O. S.), but 

 Thiele (Kieselschwamme v. Ternate II, Abhandl. d. Senckenberg. nat. Gesell. XXV, 953) has correctly 

 rendered an accouut of the fact that the type of this genus, C. clegans O. S., is a quite different sponge. 

 Thiele means, in the place quoted, that the species belonging here may be kept in the genus 

 Myxilla, whereas my opinion is that it is necessary to place them in a separate genus with the diag- 

 nosis given above, and I call this genus Dendoricella. Its most important character is that the skeletal 

 spicules are plainly and really diactinal. 



The eldest species of the genus is D. Schmidtii Ridley (Zool. Coll. of < Alert-, 432, PI. XLI, fig. aa). 

 Dendy has later (Proc. of the Royal Soc. of Vict. VIII, 28) established a species, D.australicnsis, which 

 is. however, according to Topsent (Rev. Suis. de Zool. IV, 455) identical with Schmidtii. Topsent, 

 in 1892, (Archiv de zool. exp. et gen. 2, X, XXII) has established two species (under Damiria), caver- 

 nosa and Prouhoi ; of these species the latter has certainlv not really diactinal spicules, but is, no 

 doubt, a Jl/yxilla (see below under M. brunnea); the former species, cavernosa. I think to be a Dendo- 

 ricella. Finally Topsent (Resultats de Campagn.scient.du Prince de Monaco, Fasc. XXV, 240, PI. Ill, 

 fig. 3, PI XIV, fig. 12) has established a species, abyss/', which, remarkably enough, he refers to Dcsma- 

 cidon, although it is a sure Dendoricella. Of Carter's Halichondria infra/ u ens (Ann. Mag. Nat. Hist. 



