bee MARINE BIOLOGY OF THE SUDANESE RED SEA. 
KENTRODORIS LABIALIS, sp. Nov. 
(?= Doris setosa, Pease, Proc. Zool. Soc. 1860, p. 26.) 
Two specimens which though somewhat different in appearance were cor- 
rectly referred by Mr. Crossland to the same species. Of the first, which 
was found under a stone on the mud-flats of Suez, he says :—‘“ Dirty white, 
with inconspicuous round light brown spots which look like pits, but are not. 
Back covered with bundles of hairs (? spicules) which form a fringe to 
mantle and gill-pocket. Back rounded ; foot narrow, deeply grooved and 
notched ; oral tentacles finger-like.” The second was found at Snakim on a 
shell of Margaritifera vulgaris attached toa buoy. Mr. Crossland says of it :— 
“Not very like the first specimen except for the tufts of hair-like spicules 
which cover it. Colour a very dark dull grey with sandy spots round mantle- 
edge and on the rhinophores and tips of gills. Gills long and rather slender, 
resembling those of a Chromodorid, but bipinnate, with numerous delicate 
branchlets.” 
Both specimens, as preserved, are much contracted and rolled up into balls, 
though they appear to have been naturally flat. The largest is about 12 mm. 
long and 7mm. broad. The mantie-margin is ample. The pockets of the 
rhinophores and branchie are not raised. The back is covered with fusiform 
tubercles, somewhat swollen below the tips. The whole dorsal surface is full 
of spicules, which project freely from the tips of the tubercles. The spicules 
are fairly straight, not branched, and have a granulated appearance externally. 
The branchize are completely retracted ; at least 8 in number, and possibly 
10, two plumes being very small. The foot is narrow, with a rather long 
free tail. The anterior margin is deeply grooved; the upper lamina is 
notched in the middle and forms two ample lappets. 
The blood-gland is purplish. The central nervous system is enclosed in a 
capsule which is spotted with purplish brown. Within the capsule are three 
pairs of fairly distinct yellow ganglia. The eyes are large and sessile with 
yellowish lenses. 
A smull labial armature consisting of fibrous-looking rods, somewhat swollen 
at the tips, was found. In both specimens it appeared as two plates, but they 
possibly represent a semicircular armature broken in two. The formula of 
the radula was in one specimen 20 x 18,0.18, and in the other 24x 18.0. 18. 
Some of the rows were shorter, but none contained more than 18 teeth. The 
teeth are simply hamate and erect, without a trace of denticulation. The 
innermost are hard to see, but apparently do not differ from the others in 
shape. The teeth increase in size from the inside outwards but the tips are 
often broken, which gives the row an irregular appearance. The outermost 
teeth are smaller and slender. 
The hermaphrodite gland forms a white layer on the liver. The genitalia 
seem to be immature, and it is probable that the specimens are not full-grown, 
