ON EXPERIMENTAL PHEASANT-BREEDING. 539 



joining, the upper part of the valve being solid and projecting 

 freely, while the carina of S. fossula has the intrapai-ietes 

 forming a thin wall on each side of the cai-ina, which is a more 

 advanced type. There is not as yet sufficient evidence to prove 

 whether A?. /oss?f^ffl was derived from S. arcuaium or not. It is 

 patent, however, that from the foregoing species subsequently 

 arose the forms grouped as Arcoscalpellum and characterized by a 

 reduction in the number of plates of the capitulum, by a sup- 

 pression of the rostrum, and a tendency towards the reduction 

 of the pair of infra-median latera. 



For help in connexion with this paper I wish to express my 

 indebtedness to Dr. F. A. Bather, Dr. W. T. Caiman, Mr. 0. P. 

 Chatwin, and Dr, P. P. C. Hoek. 



Ke?/ to Species mentiojied. 



A. Carina without intraparietes, parietes not 



reaching to the basal inai'gin and bent almost 



at right angles to the tectum S. simplex Darwiu. 



B. Carina with intraparietes bent inwards and 



joining, the upper part of the valve solid and 

 projecting freelj^ 



1. Carina with basal margin rounded S. accumulaium Withers. 



2. Carina with tectum tlatlj'-arched transversely, 



and marked witli numerous fine longi- 

 tudinal ridges S. arcnatiim. Darwin. 



3. Carina with tectum flatly-arched transversely, 



and marked with three prominent longi- 

 tudinal ridges, one central, and one on 

 either side separating the tectum from the 

 parietes_ S. trilineatum Darwin. 



4. Carina with tectum strongly convex trans- 



versely and marked with several longitudinal 



ridges 8. solidulum Steenstrup sp. 



5. Carina with tectum strongly convex trans- 



versely with smooth surface S. maximum var. c_i/Undra- 



C. Carina with intraparietes forming a thin wall [ceiun Darwin. 



on each side of the valve. 



1. Carina with tectum and parietes smooth, 



dorsal surface and inner margin much 



arcuated S. hastatum Darwin. 



2. Carina with tectum bordered on each side hj 



a large, protuberant, flat-topped ridge S. fossula 'Da.r\f\n. 



28. Experimental Pheasant-breeding, 

 By Rose Haig Thomas, F.Z.S. 



[Received December 4, 1911 ; Read February 6, 1912.J 



(Plates LXIV.-LXVII.*) 



The experiment with which I deal in this paper was under- 

 taken to test the truth of the i-esult of one previously made 

 (P.Z. S. 1909, pp. 884-885), in which it was shown that a male 

 Pheasant had transmitted to his female offspring of the second 



* For explanation of the Plates see p. 54.1. 



36* 



