NO. 1/ NEW SPONGES— DE LAUBENFELS 1 5 



OXEOSTILON Ferrer- Hernandez 

 OXEOSTILON BURTONI, n. sp. 



Holotype. — U.S.N.M. no. 22347; from station 52, latitude 19° 10' 

 25" N., longitude 69°2o'55" W. to latitude i9°io'o5" N., longitude 

 69°2i'25" W., February 16, 1933, 14 to 22 fathoms. 



This specimen is a mass about 3 by 6 cm, having an irregular sur- 

 face. It is profusely covered with grooves about 3 mm deep and of 

 similar width, separated from each other by protrusions and ridges of 

 approximately the same dimensions. The color is pale drab, and the 

 consistency is notably spongy. The surface is minutely hispidated, not 

 by protruding spicules alone, but by little fibers scarcely 50 jx in di- 

 ameter and less than 500 ^ high. In some of the grooves there seems 

 to be a sort of dermis, roofing over subdermal cavities. If there were 

 pores in this dermis, they are closed, because at present the surface 

 does not reveal any evident openings. Internally there is a confused 

 structure, with a much denser axial region making up about one-third 

 of the total diameter of the sponge, but not having sharply defined 

 boundaries. The spicules show great variation both in size and shape, 

 some being clearly oxeas, others being definitely styles. Representa- 

 tive spicule measurements, selected from many to give an indication 

 of the variation, are as follows : 22 /t by 330 fx, 24 /a by 400 fi, 6 iihy 

 '520 /A. In general the styles and oxeas are of about the same size, 

 although the styles show perhaps greater variation than the diactines. 



The one other species at present referred to Oxeostilon is annan- 

 dalei Ferrer-Hernandez (1922, p. 255). Unlike the West Indian 

 form, this one from Spain has a smooth surface without the fibrous 

 hispidation, and some of the spicules are faintly polytylote, or mal- 

 formed in other ways. No other species can be cited at present as 

 being closely related here. 



Named for Maurice Burton, of the British Museum. 



OPHLITASPONGIDAE, n. fam. 



This family is established for genera from the family Microcionidae 

 de Laubenfels that differ from typical species of that group in having 

 the echinating spicules not at all spined. While at first glimpse this 

 appears as a fine distinction, it will be noted that for just this slight 

 variation the family approaches closely to Axinellidae, which is often 

 regarded as far removed from Microcionidae. In order to distinguish 

 this new family from Axinellidae, one must point out that many (but 

 by no means all) of the genera in Ophlitaspongidae have the tylote 

 modification of their exclusively monaxon megascleres, and that they 



