358 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



seems to me there is, lies in the result that the assignment of a par- 

 ticular form to a group becomes less dubious than where the attempt 

 is made to divide the whole genus into subgenera, each of which is 

 supposed to be definitely marked by a particular character or com- 

 bination of diameters. If the character or combination is distinctly 

 developed, a subgenus in the sense proposed here is ready to receive 

 the form. If such features are absent, or are not well marked, the 

 form goes in the body of the genus. This remains heterogeneous, 

 and yet it may be greatly reduced in extent by the institution of the 

 several homogeneous subgroups. Such a treatment will, I believe, in 

 the end make it easier both to place and find particular species. 



In the body of the genus, as here understood, will fall the species 

 enumerated under Tetilla by Lendenfeld, 1903 plus T. (Tethyo- 

 psilla) stewartii Lendenfeld, 1888 (p. 45), and the following species 

 not included in, or published later than, his synopsis : 



T. {Chrotella) minuta (Wilson), 1902, page 383. 



T. longipilis Topsent, 1904, page 97. 



T. (Chrotella) amphiacantha (Topsent), 1904, page 96. 



T. poculifera Dendy, 1905, page 90. 



T. (Tethyopsilla) raetaclada Lendenfeld, 1906, page 135. 



T. (Tethya) sansibarica Lendenfeld, 1906, page 89. 



T. (Tethya) vestita Lendenfeld, 1906, page 95. 



T. (Tethya) gladius Lendenfeld, 1906, page 97. 



T. (Tethya) hebes Lendenfeld, 1906, page 98. 



T. (Chrotella) ibis (Row), 1911, p. 311. 



T. (Tethya) seriea (Lebwohl), 1914, page 13. 



T. dactyloidea, var. lingua Dendy, 19166, page 104. 



T. pilula Dendy, 19166, page 104. 



T. barodensis Dendy, 19166, page 105. 



T. furcifer Dendy, 19215, page 9. 



Three of the species included in this report fall here: T. dacty- 

 loidea (Carter), T. ciliata, and T. spinosa. 



For the species falling under Cinachyrella see below under that 

 heading. 



TETILLA DACTYLOIDEA (Carter). 



Tethya dactyloidea Carter, 1869, p. 15. 

 Tetilla dactyloidea Sollas, 1888, p. 44. 



About five dozen specimens taken at " Tacloban Anchorage, about 

 ship; hand dredge." 



Since Lendenfeld's Tetraxonia, 1903, where (p. 18) the references 

 are given, the species has been recorded by Derid}\ 19165 (p. 102, 

 pi. 2, figs. 10 a-c), for the coast of Kattiawar (Arabian Sea). A 

 variety living in fresh water has been described by Annandale, 1915. 



In the Albatross specimens the sponge body is, as usual, elongate 

 and subcylindrical, with a terminal osculum leading from a cloaca, 



