122 THE ENTOMOLOGIST. 



series of M. neustria for comparison with a hybrid brood, resulting 

 from a pairing between a male neustria and a female castrensis. Only 

 a portion of the batch of from two hundred to three hundred ova that 

 the female laid hatched. The la?t of the females that eventually 

 emerged was three weeks ahead of the first male, and most unfortu- 

 nately before any males of either of the parent species, so that the 

 fertility of the hybrid females could not be tested. Their bodies 

 apparently contain few, if any, ova. Mr. Bacot said lie had every 

 reason to believe, however, that he obtained pairings between the 

 hybrid males and females of cdstrensis, in addition to fresh pairings 

 between males of neustria and females of castrensis, and therefore had 

 hopes of continuing the experiment next summer. Mr. J. W. Tutt 

 said this was the first time any exhibition of experiments of the kind 

 had been made before the Society by British investigators, though 

 Mr. Merrifield had shown a number of crosses bred by Dr. Standfuss. 

 In this case the colouring of the female hybrids, departing from the 

 usual colour of the females of the parent species, appeared to approach 

 more nearly in tint the females of the closely-allied Alpine species 

 M. alplcola, and it would be interesting to discover whether the 

 peculiarity of colour in the hybrid females really marked a tendency 

 to revert to a more primitive type of coloration, such, for example, 

 as that exhibited by M. alpicola. The sexes, as exhibited, were 

 very clearly distinguishable, and there was not much tendency to 

 gynaudromorphism, though of sixty or seventy specimens almost every 

 female showed some signs of male coloration. — Mr. 0. E. Janson 

 exhibited a pair of Stephanocrates dohertiji, Jord., a goliath beetle 

 discovered by the late W. Doherty in the highlands of British East 

 Africa. — -Dr. T. A, Chapman exhibited cocoons of a Limacodid moth 

 from La Plata, with empty pupa-cases of a dipterous parasite of the 

 genus Sijstropus, obtained from Herr Heyne, who unfortunately had no 

 imagines either of the moth or the fly. There is a close resemblance 

 between the two pupa-cases, as seen by comparison with genuine 

 Limacodid cases. The resemblance is, however, not merely of appear- 

 ance, but functional also. Tlie moth pupa, i.e. the moth itself inside 

 the pupa-case, almost certainly by inflating itself with air, to secure 

 greater size and a stifiened epiderm as a basis of muscular action, 

 exerts an end-to-end pressure within the cocoon, and so forces off a 

 lid. It is here that the beak or " cocoon-opener," with which the 

 pupa is armed, is useful as determining that the fracture shall be at 

 the right end, making the lid split off here, under much less pressure 

 than would be efficient without it, and leaving no chance for fracture 

 to occur at the wrong end when pressure is equally distributed. The 

 Systropus breaks off a similar lid, no doubt by similar end-to-end 

 pressure to that exerted by the moth, Diptera having highly developed 

 the habit of inflating themselves with air, at emergence from the 

 pupa. This pupa also has a beak very like that of the Limacodid, but 

 even stronger and sharper. — Dr. Chapman also showed a Bombyliid 

 pupa-case from West Africa, very like that of some British forms, the 

 head-armature of which is not a "cocoon-opener," but an excavating 

 or navvying machine, for use in burrowing a way out of loose soil, 

 such as that in which solitary bees' nests are found. The pupa of an 

 African species of practically the same habits as this South American 



