12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 9I 



long. These superficially appear as oxeas, but in reality their exact 

 nature cannot be made out easily. At each end of the spicule there is 

 a series of stages like steps, each successively suddenly smaller than 

 the proximal one, until the distal unit is very minute. 



This peculiar spiculation is found as an unusual modification in 

 many sponges, but its extreme development is found in only a few 

 genera, of which a typical one is Anacanthaca Row, whose other 

 species {A. nivea Row, 1911, p. 329) was from the Red Sea and had 

 its surface marked by grooves into polygonal areas, indicating close 

 relationship to the West Indian sponge A. rea. Its color, however, 

 was white, instead of dark pinkish gray, and its spicules about half 

 again as large. 



Family HALICHONDRIIDAE Gray 



DACTYLELLA Thiele 



DACTYLELLA RHAPHOXEA, n. sp. 



Holotype. — U.S.N.M. no. 22303 ; from station 26, latitude i8°3o' 

 20" N., longitude 66°22'o5" W. to latitude i8°3o'3o" N., longitude 

 66°23'o5" W., February 7, 1933, 33 to 40 fathoms. 



This specimen has a small central mass, about 1.5 cm in diameter, 

 from which arise three digitate projections, 5 to 7 mm in diameter 

 and reaching a total length, in one case at least, of 6 cm. The color 

 is dark pinkish gray. The consistency is cartilaginous, and the sur- 

 face is even. The dermal structures are very fleshy, pierced by aper- 

 tures about 200 IX in diameter, covered with sieves in which the open- 

 ings are about 30 p. only. It is not clear whether these are oscules or 

 pores, or if perhaps some may not be inhalant, while others are ex- 

 halant. The internal structure is dense, fine-grained. There is an 

 axial region of parallel spicules making up the bulk of the sponge, 

 around which a vague external portion comprises spicules more or 

 less in confusion, not in any definite layer; nor is there any sharp 

 dividing point between the endosome and ectosome. The spicules are 

 altogether oxeas of tremendous size variation, frequently reaching 

 15 ju, by 5,000 ju, but also very abundant ones are only i /* by 50 /x ; this 

 is especially true of those in the dermis. Possibly the larger ones are 

 megascleres and the smaller ones microscleres, but the considerable 

 number of intermediate forms renders this doubtful. 



The only other species at present referred to the genus Dactylella 

 is hilgendorfi Thiele (1898, p. 56), a Japanese sponge that agrees 

 rather closely with the West Indian form D. rhaphoxea, except that 



