Calalogiie of Non-Calcai'emis Sponges. 27 



Histoderma verri/cosiaii, Carter. 



Histioderma verriicosuvi, Carter, A.M.N.H., December, 1886, 

 p. 452. 



Histioderma poIymasteides,Q,»xi't\\ A.M.N.H., December, 1886, 

 p. 453. 



The isochelte may be extremely rare. In R.N. 392 and 398 

 I have not been able to find any, and in B.M. sp. 36 I could only 

 find one. 



H. polymasteides would appear from the description to be 

 merely a more robust variety, but I have seen no specimen. 



R.N. 392; 398; 627 (x, 19 f ; "buff"); 808 (s. 5); 1189. 



B.M. sp. 36 {'■'•Histioderma verrucos7e}n" Reg. 86-12-15-74). 



Genus Amphiastreila, nov. gen. 



Sponge consisting of a massive body throwing oft' hollow fistula? 

 from the upper surface and (sometimes) with root-like processes 

 below. Body with a dense cortex of horizontally-placed spicules. 

 Megascleres diactinal, strongyla or tylota. Microscleres amphi- 

 asters (birotuiates), to which others may be added. 



The erection of a new genus for Carter's Phlixodictyon hiroiuli- 

 Jerum seems to me necessary. The name Fkhvodictyon was first 

 used by Mr. Carter for entirely different forms. 



Amphiastreila Inroiulifera, Carter, sp. 



P/iiivodictyon Inroiuliferjun, Carter, A.M.N.H., December, 

 1886, p. 447, pi. X., figs. 1-5. 



As this very remarkable species is hitherto known only from a 

 fragment (one of the branching tubes), I propose to supplement 

 Mr. Carter's detailed account with the description of a second 

 specimen dredged by Mr. Wilson. 



Sponge massive, depressed, sessile, irregular, thickly encrusted 

 with shell debris and other rubbish. Lower surface sending out 

 numerous rather slender, elongated, rootlike processes, attached 

 to which are pebbles, (fee. Upper surfaces giving off a few 

 irregular, slender, elongated fistula;, most of which are closed at 

 the apex (? two open naturally). These hollow fistulee branch 

 irregularly, and some have distinctly reticulate walls. The body 

 of the sponge is dense and compact, and is enclosed on all sides 



