122 D. KEILIN. 



single female still living had a rounded abdomen, which showed that its ovaries were 

 well developed. This female was put in another breeding vessel, and the dissection 

 of this fly, done three days later, showed that its ovaries were perfectly matured. 

 The breeding vessel (terrarium) was well examined. Kurdjumov found no eggs on 

 the plants, but in the earth he found at no great depth two eggs similar to those 

 discovered in the lower chambers of the ovary of the dissected fly. In one of these 

 eggs the black mouth-parts of the larva were visible through the egg- covering. 



On 9th November this egg was taken to the laboratory and on 12th November the 

 larva protruded the anterior part of its body from the egg and died in this position. 

 Kurdjumov inferred from the facts (a) that the frost did not kill the egg, and (b) that 

 as the larva hatched as soon as it was transferred to a warm place, it is the egg which 

 represents the hibernating stage of L. coarctata. He next describes the first stage 

 larva ; but his description, and especially his figure 26, convince me that neither 

 eggs nor larva belong to the developmental cycle of L. coarctata. 



Fig. 1. Mouth-parts of Kurdjumov's primary larva. 



It is quite sufficient to look at Kurdjumov's fig. 26, which I reproduce here (fig. 1), 

 and which represents the mouth-parts of his primary larva, to establish from all the 

 details of the structure he delineates that it pertains to a carnivorous larva.* 



If we compare the mouth-parts of this supposed first- stage larva with those of a 

 full-grown larva of Leptohylemyia, we can easily see that the difference is not one 

 which we usually find between the primary and third stage larva of the same species. 

 The difference is such as can only exist between two different ethological groups. 

 As figure 2 shows, the mouth-parts of a full-grown Leptohylemyia larva are very like 

 those of one of the phytophagous Anthomyid larvae (Pegomyia nigritarsis, or even 

 those of Adia genitalis, discovered by Kurdjumov). | The first stage Leptohylemyia 

 larva should be then very similar to the primary phytophagous larva and it probably 

 resembles closely that of Adia genitalis (fig. 5 of Kurdjumov). 



Kurdjumov's description contains two other points which show that his primary 

 larva does not belong to Leptohylemyia, for he states : (1) that the last abdominal 

 segment is round and without the protuberances which are very characteristic for the 

 full-grown larva of Leptohylemyia ; (2) that the posterior spiracles of his primary 

 larva have three clefts and closely resemble those of a third stage cyclorrhaphous 



* See : D. Keilin. Recherches sur les Anthomyides a larves carnivores. Parasitology, 

 ix, no. 3. 



f I am much indebted to Messrs. C. Warburton and F. E. Petherb ridge for the larvae of 

 Leptohylemyia coarctata herein referred to. 



