50 THE VOYAGE OF H.M.S. CHALLENGEE. 



Toxochalina robusta, Eidley. 



1884. Toxochalina robusta, Ridley, Zool. Coll. H.M.S. "Alert," Brit. Mus., 1884, p. 403, pi. 



xsxix. fig. G ; pi. xli. figs, n, n. 



We identify with this species a single small, irregularly branched specimen from 

 Bahia, which agrees very closely in microscof)ical structure, though of not nearly such 

 robust growth as the type. It may be only a young specimen. 



Locality. — Off Bahia, 7 to 20 fathoms. One specimen. 



Habitat— Fort Jackson (Ridley, " Alert ") ; off Bahia (Challenger). 



Subfamily 3. Tedaniin.e. 

 1886. Tedaniina, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. p. 335. 



Megasclera always of two forms : — (1) Monactinal, styli, forming the main skeleton ; 

 (2) Diactinal, tylota or tornota, dermal. Microsclera always present in the form of 

 rhaphides. 



Two genera of this subfamily are distinguished, viz., Tedania, in which the stylus 

 is smooth, and Tracliytedania, in which it is more or less spined. In both genera the 

 form is usually massive, amorphous, and both genera are characteristically shallow-water 

 forms. The dermal spicules are susceptible of very great variation in the different 

 species, being sometimes bicapitate (tylota), and at other times hastately pointed (tornota). 



Genus Tedania, Gray (Pis. XL, XXIII. , XXIX.). 



1862. Reniera, 2-iars, Schmidt, Spong. Adriat. Meer., p. 75, &c. 

 1867. Tedania, Gray, Proc. Zool. Soc. Lend., May 9, p. 520. 



Styli smooth. 



Gray's original diagnosis runs — " Sponge lobed, crested, with a lateral tube ending 

 in an open mouth. Spicules of three kinds : — 1. Clavate, needle-shaped. 2. Fusiform, 

 very slender, elongate, sometimes flexuous. 3. Cylindrical, with rather thicker, blunt 

 ends." 



The range of external form exhibited by this genus is shown by the Challenger 

 dredgings to be a very remarkable one indeed ; hitherto known only by more or less 

 massive or digitate specimens, we have had to add to the genus two new species, 

 Tedania infundibuliformis and Tedania actiniiformis, characterised by very specialised, 

 though quite different, external forms ; the former (as yet known by only one specimen) 

 being funnel-shaped, and the latter " actiniiform," ^ with oscular projections on the top 

 and a definite zone of pores. 



' Like an Actinia. 



