SILICIOUS AND HORNY SPONGES WILSON. 333 



Holotype.— Cat. No. 21297, U.S.N.M. 



The Albatross sponge plainly lies in the neighborhood of J as pis 

 (plus Coppatias) in the Epipolasidae as a form without astrose rnic- 

 roscleres. Closely related sponges without microscleres are the spe- 

 cies described by Topsent (1896) and Dendy (1905) under Spongo- 

 sorites. In Spongosorites, as emended by Dendy (1905, p. 182), the 

 choanosomal skeleton is composed of oxeas scattered thickly in all 

 directions, the ectosomal skeleton is especially dense and is composed 

 of similar but smaller, tangentially placed, oxeas. Dendy (1905 and 

 19215), would transfer this genus to the Axinellidae, but I see no 

 good reason for doing so. 



Acanthoxifer Dendy (1905, p. 156) is, I take it, also a related 

 sponge. In this genus the main skeleton is a confused reticulation 

 of, chiefly smooth, oxeas ; cortical skeleton made up of radial brushes 

 of, chiefly spined, oxeas; microscleres, trichodragmas. Anaeanthaea 

 Row (1911, p. 329) is a similar form in which none of the oxeas are 

 spined. These two genera are placed by Dendy (1905) and Row 

 (1911) in the subfamily Heteroxyinae Dendy (referred now, Dendy 

 1921. p. 25, to the Desmacidonidae) created by Dendy for Acan- 

 thoxifer and for Ileteroxya Topsent, which he would remove from 

 the Donatiidae. But their place, as well as that of Spongosorites, 

 including the Albatross species, seems rather to be in the neighbor- 

 hood of Jaspis. 



The several genera are certainly close together. In respect to the 

 ectosomal skeleton, the Albatross sponge resembles on its oscular 

 face (spicules tangential) Spongosorites sensu Dendy, on its pore 

 face (spicules in radial brushes) Acanthoxifer and Anacanthaea. 

 In the choanosomal skeleton all the forms are essentially alike. It 

 does not seem possible therefore to retain these genera as separate 

 groups. Spongosorites may easily be sufficiently enlarged to include 

 the other forms, and the definition of this genus, employed above, 

 represents an attempt to do this. Dendy (19215, pp. 124—126) dis- 

 cusses the genus and describes a new species from the Indian Ocean. 



Family DONATIIDAE. 



Tethyidae Authors. 

 Donatiidae Baer, 1906. 



Massive, discoidal, or incrusting forms. The megascleres are 

 radially arranged rhabds: styles (=strongyloxeas, sometimes fusi- 

 form) or oxeas. Ectosome often but not always differentiated to 

 form a fibrous cortex, frequently furnished with radiating mic- 

 rorhabds. The microscleres exclusive of microrhabds, which are 

 not always present, are euasters, sometimes of two sorts. But! micro- 

 scleres may be entirely absent (Tuberella, Trachya, Ileteroxya). 



