56 MARINE BIOLOGY OF THE SUDANESE RED SEA. 
which the polyps are thickly clustered in catkins. A typical branch 
separated from the common basis corresponds closely to the figure given 
by Klunzinger (1877). 
In more than one specimen we found no trace of spicules, but as these 
specimens were badly preserved we suppose that some acid had been acciden- 
tally added to the preservative. 
Localities —Suez; Coral shoal of Kal el Kebira in Suez Bay ; Khor Abu 
Hamama, 10 fathoms, muddy bottom. Previously recorded from Red Sea, 
Zanzibar, New Britain. 
LirHoruytum Brassicum (May). (Plate 5. fig. 4.) 
See W. May, 1899, loc. cit. p. 189, fig. 22. W. Kiikenthal, 1903, p. 120. 
We have figured (PI. 5. fig. 4) a specimen which agrees in essential 
features with Lithophytum brassicum, though it is somewhat divergent in its 
mode of growth and general appearance. It is fixed to a piece of Millepore 
and rises toa height of 20 mm., with a maximum breadth of 55 mm. It 
shows about sixty subglobose heads, each bearing about a score of polyps 
which are deeply retracted. The colour is a dull light brown. 
Locality—Edge of leeward reef, Suakim Archipelago, Tella Tella Kebira. 
Previously recorded from Zanzibar. 
LITHOPHYTUM THYRSOIDES (hrenberg). 
= Ammothea thyrsoides, Ehrenberg. See W. Kukenthal, 1903, doc. cit. p. 109. 
Several fine specimens of this common species are included in the collection. 
They consist of a common basis from which cylindrical stalks rise parallel to 
one another. The polyps arise directly from the ends of the stalks. The 
spicules of the stalks and polyps are very slender transparent spindles with 
few warts. 
The following measurements were taken of length and breadth in milli- 
metres :— 
(a) Polyp-spicules: 0°3 x 0:01 5 0:28 x 0:01; 0:2 ><0;01 10:la050ie 
Om (0:01 01 Sc0540;05)>< O01 
(b) Stem-spicules : 0°46 x 0°02 ; 0°37 x 0°02 ; 0°35 x 0°02 5 0:27 x 0:02 ; 
O52 <<0;0i 
The colour of the preserved specimens is yellowish-brown ; in life they 
were dull brown. 
Locality —Outer Park of Suakim Harbour. Previously recorded from 
Red Sea, Indian Ocean (Tumbatu), Zanzibar. 
LITHOPHYTUM CROSSLANDI, n. sp. 
A common stem, 2 cm. broad and 1°5 em. high, gives origin to four limp 
branches showing longitudinal furrows. These branches are 13, 12, 9, and 
7 cm. in length respectively, and carry secondary branches on which the 
