SPONGES FROM THE ABROLHOS ISLANDS. 509 
osculum raised on a small papilla. Pigment grannies are present in the 
large specimen, absent in the small one. 
The skeleton arrangement and spieulation agree closely with the descrip- 
tions given by Topsent and Wilson. 
We propose to revive here Grray's generic name Aaptos [1867], because 
we can find no adequate reason why Keller's genus Tuherella [1880] 
should stand in place o£ it, though we regard his species Tuherella tethyoides 
as synonymous with Anrorina aaptos Schmidt. We have revised and 
brought up to date Topsent's synonymy list, which we think can be definitely 
accepted. 
Carter [1870] described a new genus and species o£ sponge under the 
name Trachya pernucleata ; after examining his preparations we think it 
justifiable to identify this species with Aaptos aaptos (Schmidt), and it is 
therefore included in the synonymy list. 
Carter [1882 A, 1886] described two more species of Trachya, viz. 
Tracliya dnrissima and Trachya horrid a ; these are probably identical with 
his original species, Trachya pernucleata. 
Tracliya globosa Cariev [1885-86] and Trachya fflobosa y&r. rugosa Carter 
[1886] are obviously lipotriajnose Tetillids, having exceedingly long, 
slender oxea for megascleres and sigmata for microscleres. 
(barter [1876, 1882 A] pi-oposed a group Polymastina in the Sub-order 
Suberitida to include his genus lYachya as well as the typical Polymastia, 
referring to Trachya pernucleata and its allies as " Geodia-\\k& forms of 
Polymastia.^' 
Although Vosmaer, Topsent and Wilson have placed the genus Tuherella 
(^ = Aaptos] in the Tethyidse (Donatiidse), we are inclined to agree more \Yith 
Carter's views ; and so, because of the arrangement of the skeleton, the 
absence of any fibrous cortex and the presence of pin-head spicules in some 
cases, we now propose to transfer it to the Sigmatotetrasonida, Family 
Clavulidse, Sub-family Suberitinre. 
Previously known Distribution. Mediterranean {Schnidt, Lendenfeld, 
Topsent) ; Gulf of Naples {Keller); Gulf of Mexico {Topsent) ; Porto Eico 
(JVilson) ; S.W. Austi'alia (Hentschel) ; Aru Islands [Hentschel] ; Okhaman- 
dal [£>endy). 
Register Nos. and Locality. III. 5, Wooded Isle ; VI. 12 h, Sandy Isle. 
43. Polymastia mammillaris (0. F. Midler) Boioerbank. 
(For literature and synonymy ride Topsent [1900].) 
There is a single small specimen, consisting of about six smooth, slender, 
thin-walled, hollow, mammiform projections, 10 to 15 mm. in length, rising 
from a plate-like base which has either been torn off a stone or from a larger 
specimen ; the surface of the base is slightly hispid. The colour in spirit is 
dull brown owing to the development of pigment granules. 
