REPOET ON THE POLYZOA. 
129 
Six under 50 fathoms — 
Retepora denticulata. 
. ,, victoriensis. 
var. japonica 
,, contortuplicata. 
,, columnifera. 
,, delicatula. 
Ten under 240 fathoms — 
Retepora apiculata. 
„ producta. 
,, crassa. 
,, phosnicea. 
„ • tessellata. 
var. ccespitosa. 
var. pubens. 
,, gigantea. 
,, lata. 
Reteporella jlabellata. 
Five under 600 fathoms — 
Retepora imperati. 
,, atlantica. 
„ cavernosa. 
,, magellensis. 
Reteporella myriozoides. 
One at 1450 fathoms — 
Retepora margaritacea. 
On the whole, therefore, the Family, as represented in the Challenger Collection, would 
seem to belong for the most part to comparatively shallow depths, and the nature of the 
bottom appears to have been indifferent; in most cases it was mud of various origin (con- 
tinental, coral or volcanic), in a few instances sand or gravel, and in one Globigerina ooze. 
3. Turritigera, n. gen. 
Character. — Zoarium ramose, arising from a calcareous expansion, encrusting foreign 
bodies, having the openings of the zooecia usually on one side only. Zooecia ventricose 
or flask-shaped, much produced and subtubular above, with several conical or columnar 
avicularian processes on the peristome. 
(ZOOL. CHALL. EXP. — PART XXX. — 1884.) Gg 17 
