STAGES OF GLOSSINA MORSITANS, WESTW. 295 



The means of the measurements of twenty pupae are as follows, in millimetres, 

 the extremes being given iu brackets : — total length, 5'53 (5 to 6) ; width, 3'2 

 (3 to 3-75) ; depth, 2-97 (2-75 to 3-25) ; width across tumid lips, 1-45 (1 to l-o). 

 It will be seen from these data that the pupa is slightly compressed in the dorso- 

 ventral diameter. 



Fig. 2. — Dorsal view of the pnparinm Fig. 3. — Puparium of Glossina morsitans; 



of Glossina morsitans, Westw. X 10. A, anterior view, showing lines of 



dehiscence ; B, ventral view of posterior 

 portion, showing anus enclosed in eye- 

 shaped area, x 10 



The larval mouth is represented on the first segment of the pupa as a small 

 black dot, while the anus is similarly marked on the mid-ventral line at the 

 junction of the eleventh and twelfth segments, and is enclosed in a small eye- 

 shaped area marked off by two small furrows, the anterior of which is formed by 

 the dividing line between the two segments (fig. 3, B). 



The line along which the pupa-case splits to permit of the emergence of the 

 imago, is indicated on the anterior portion of the puparium as a small ridge 

 directed laterally. This ridge passes dorsally around the mouth region as a 

 slight curve, and is shown in fig. 3, A. 



Duration of tlie Pupal Stage. 



Owing to pressure of other work, it has been impossible to determine the efli'ect 

 of temperatiu'e and humidity on the length of the pupal period. The pupae, as 

 they were obtained, were j)laced in glass tubes and left exposed to the laboratory 

 air without any protection. In these circumstances the time which has elapsed 

 from the birth of the larva to the escape of the imago has varied from 47 to 53 

 days. 



In conclusion, I should like to express my indebtedness to Mr. LI. Lloyd, the 

 Entomologist of this Commission, for suggestions, and for the accompanying 

 drawings. 



Nawalia, N.E. Ehodesia, 



August 21, 1911. 



22036 B 



