88 THE SPONGES. 



TETRACTINELLIDA Marshall. 



CHORISTIDA Sollas. 



THENEIDAE Sollas. 



Thenea Gray. 



1867. Thenea Gray, 1867, P- 541. 



1888. Thenea Gray, Sollas, 18S8, pp. 59,95. 



1894. Ancorina pars Lendenfeld, 1894, p. 96. 



1894. Thenea Gray, Topseut, 1894, p. 375. 

 1898. " " Tluele, 1898, p. 21. 



1902. " " Topseut, 1902, p. 10. 



1903. Ancorina {Thenea) 0. Schni., Lendenfeld, 1903, p. 53. 



Thenea fenestrata (0. Schmidt) Sollas. 



Plate 13, Figs. 2-4, 6, 7, 9. 



1880. Tisiphonia fenestrata 0. Schmidt, 1880, p. 71, Taf. X. Fig. 2. 



1882. Thenea muricata (Bwk.) Gxa.^ pars, Vosmaer, 1882, pp. 6, 7, 13. 



1885. " " " " , Vosmaer, 1885, p. 4. 



1888. Thenea fenestrata (0. Schmidt) Sollas, 1888, p. 71, PI. VIII. Figg. 1-8. 



1903. Ancorina {Thenea) fenestrata (0. Schm.) Lendenfeld, 1903, p. 55. 



Station S4OO, 8 specimens; Station 341S, 3 specimens; Station 8362, 5 

 specimens. 



The specimens are all small, the diameter ranging from 15 to 25 mm. 

 Both upper and lower surfaces are convex, but the shape of the body 

 varies considerably, being in some cases (Fig. 2, Plate 13) strongly 

 compressed in the vertical axis, in others (Fig. 9, Plate 13) compressed 

 in one of the horizontal axes, and again with all the axes about equal. 

 The upper surface bears a single osculum, more or less centrally or very 

 excentrically placed, at the apex of a protuberance. The osculum is 

 commonly surrounded by a dense spicular fringe up to 3 mm. high, but 

 the fringe is absent in some specimens. The color is grayish. The 

 surface is comparatively even, and in general hispid to the eye, but ap- 

 pearing smooth on parts of some specimens. From the under surface 

 several slender roots project, most of which are broken off close to the 

 body. 



The pore areas vary in number from two to four, and are separated 

 by comparatively wide intervals. The width of the area (in the horizontal 

 plane of the sponge) is often about equal to the height (Fig. 9, Plate 13), 



