558 MR. F. E. BEDDARD ON A NEW (Deen; 
time, but in 1903 the mating a was repeated in the experiment y, 
in which the cdentical birds used in a were again mated together. 
In this experiment a uniform generation was obtained. A pair 
of birds bred in this F. 1 generation were mated together and the 
result is recorded in exp. é. 
The total results of the mating of Barb and Nun are :— 
(Exp. a, y) F. 1: shell present 2; shell absent 10. 
(Exp. (3, c) F. 2: shell present 3; shell absent 11. 
I can also mention here that two birds which were crosses, in 
the F.1 generation, between a Nun and a Fantail, kindly sent 
to me by Miss Thiselton-Dyer, showed no trace of “shell.” These 
birds were not bred from. 
The experiments here recorded form part of a larger investi- 
gation into heredity in Pigeons still in progress, which has been 
subsidised by the Government Grant Committee of the Royal 
Society. 
I am indebted to Mr. J. Lewis Bonhote for raising and recording 
birds bred in Exp. 14, also to Mr. R. J. Elwell for raising birds 
in Exps. 9 and 12. 
I have also to thank Mr. Bateson, who has most kindly 
supervised all the experiments. 
8. On a new Species of Worm of the Genus Pontodrilus from 
the Shores of the Red Sea. By Frank H. Bepparp, 
M.A., I'.R.S., Prosector to the Society. 
[Received October 5, 1905. | 
(Text figures 78 & 79.) 
The specimens of Pontodrilus upon which the following 
description is based were kindly placed in my hands by Mr. Cyril 
Crossland, F.Z.8. They were collected by that gentleman “in clean 
shell and coral sand on the shores of an islet in Khor Dongola, 
on the Soudan coast.” Mrz. Crossland further informed me that 
the worms “ live about the highest level at which the sand is kept 
wet by the sea. As there is practically no rainfall the water in 
which they live is undiluted by rain almost always. A species of 
Nereis and some Crustacea share this habitat.” There is thus no 
doubt about the purely marine surroundings of this Pontodrilus, 
which so far agrees with the majority of the species of the 
genus. 
The general aspect of the worms was like that of the other 
species of Pontodrilus with which I am acquainted. 
Thelength of the largest and fully mature example was 102 mm., 
the size being thus about the average size of the species of this 
genus. 
