1906.] ox BREEDIXG EXPERIMEKTS WITH LEPIDOPTERA. 125 



young (see text-fig. 48). The little Lemur was born while the 

 parents were in Mr. Gilbert's possession. The pair were turned 

 out into a garden in the first week of July 1905 and left out 

 until the 24th of that month ; and Mr. Gilbert was inclined to 

 believe that the mating took place during this period of freedom. 

 However that may be, the young one was born on Sept. 26th ; 

 and if Mr. Gilbert's surmise as regards the time of pairing be 

 correct, the period of gestation may be estimated as between ten 

 and twelve weeks. 



For the first two months of its existence the little one clung to 

 its mother's breast. It afterwards transferred itself to her back, 

 as shown in the photograph, which represents the animal when 20 

 weeks old, or about half-grown. Towards the end of January 

 (that is to say, when some four months old) the young one began 

 to go about on its OAvn account, alwaj^s returning, however, to its 

 mother's back when disturbed by anyone entei'ing the room. By 

 the middle of February it was partly weaned, and was feeding 

 readily upon bananas and milk. 



Dr. A. Smith Woodward, F.R.S., F.Z.S., exhibited a new 

 drawing of the skeleton of the Triassic Rhynchocephalian, Rhyncho- 

 saurus ariiceps, from the Keuper Sandstone of Shropshire. He 

 pointed out the difierences between this ancient reptile and the 

 modern Sphenodon, especially noting the gi^eat expansion of its 

 coracoids and ischia, and the probably diminutive size of its 

 sternum. He inferred from the everted rims of the upwardly- 

 turned orbits, and from the sigmoidal bend of the femur, that 

 Rhynchosaurus was to a great degree aquatic in habit. 



The following pa.pei'S \^'ei'e read : — 



1. On Breeding Experiments with Lepidoptera. By 

 L. DoNCASTER, M.A., F.Z.S., Mackiunon Student o£ 

 the Royal Society, and the E,ev. Gr. H. Raynor, 



M.A.,-F.E.S. 



[Received December 28, 1905.] 

 (Plate VIII.*) 



I. — Angeroxa prunaria. (Plate VIII. fig. 1 .) 



(Experiments by L. Doncaster.) 



In the summer of 1903 I began breeding-experiments with 

 Angerona prunaria and its var. sordiata, in order to find out how 

 the two forms behaved in inheritance. My material was obtained 

 from two sources : pupae of both varieties were bought from a 

 dealer, and Mi-. 0. P. Pickett of Leyton gave me eggs which he 

 had bred. In neither case did I know the ancestry of the 



* For explanation of tlie Plate, see p. 183. 



