REPORT ON THE TETRACTIHELLIDA. 
49 
Surface hispidatecl by projecting spicules, chiefly oxeas, which are frequently borne at 
the ends of band-like processes ; these and the numerous apertures give the sponge 
a characteristic ragged appearance. 
Spicules. — I. Megascleres. 1. Oxea, isoactinate, 3 ‘34 by 0'045 mm. 2. Protrisene, 
rhabdome 4‘0 mm. (and over?) by 0'008 mm.; cladi 0'13 mm. long; chord 0'048 mm. 
3. Anatrixne, rhabdome 4*0 mm. (and over?) by 0*004 mm.; cladi 0*045 mm. long; 
chord 0*058 mm. 
II. Microsclere. 4. Sigmaspire, 0*034 mm. long. 
Habitat. — King’s Island, Mergui Archipelago, coast of Burmah. 
Remarks. — The large cavities beneath the ectosome may be of the nature of 
vestibules, as indeed Dr. von Lendenfeld when I called his attention to them appeared 
to think they were ; and it is possible that they may prove of sufficient importance for 
generic distinction of the species. 
The sigmaspires are much longer than usual, and the cladi of the anatrisenes much 
shorter. 
Tetilla (?) stipitata (Carter). 
Tethya stipitata, Carter, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. p. 460, 1886. 
Sponge fig-shaped, stipitate ; stem hard, dense, cylindrical, expanding into the 
body of the sponge above, and into a root-like mass below, which is charged with 
coarse sand. Oscules several, the largest on the summit. 
Spicules. — I. Megascleres. 1. Oxea isoactinate, 3*5 by 0*032 mm. 2. Radical 
anatrisene; cladi short and stout, only slightly reflexed backwards. 3. Radical amplii- 
trisene, very variable in form and size; rhabdome 0*32 by 0*032 mm., and 0*56 by 
0*019 mm.; cladi simple, 0*15 mm. in length. 
II. Microscleres. 4. Sigmaspire, 0*024 mm. in length. 5. Radical microstrongyle, 
variously curved, from a parabola to an almost straight line, minutely spined, 0*059 mm. 
long. Protri^nes and somal anatrisenes absent. 
Colour. — Eeddish-purple above, white below. 
Habitat. — Port Phillip Heads, South Australia. 
Remarks. — For the opportunity of examining prejDarations of this sponge I am 
indebted to the kindness of Mr. Carter, who has not only sent me mounted spicules, 
but a coloured illustration of the whole sponge. It is one of the most remarkable of 
the Tetillids, distinguished by a conjunction of unique characters. The rigid stem is 
peculiar to it, so also are the amphitrisenes which occur only in the stem, and the 
curved microstrongyles, which are also chiefly confined to the stem. The sigmaspires are 
(ZOOL. CHALL. EXP. PART LXIII. 1887.) RlT 7 
