150 l-'"'.^- 



pi'oliahly due to some isolated larvae having pupated at a later date 

 than the niajoritv. 



'Die ])uparia eolleeted were plaeed on damp sea-sand in small vessels 

 covered at the top with gauze, and the sand was kept moist. Between 

 September 18th and 20lh numerous flies emerged ; emergences then 

 became fewer, and none took place after the end of September. INIost 

 of these flies were let go, and their empty jiuparia thrown away ; but 

 some few puparia were isolated, and they and the flies bred from them 

 were ])rcserved for purposes of identifieation. The flies proved to Tx^ of 

 two s])ecies. ('nelopa pilipes Hal. and Fucomyia (jritvis Hal. The two 

 bred examples of the latter differ considerably in size, but Mi-. C. Cj. Lamb 

 and Mr. J. E. Collin agree in regarding them as belonging to one species, 



'J'here still i-emained a large number of puparia from which nothnig 

 liad emerged, and these . were brought back to Cambridge early in 

 October, being ke|)t under the same conditions and disturbed as little 

 as possible. The vessels were placed in a room where a fire was burning 

 during part of the day when the weatlier became cold, and tlie sand was 

 moistened every week. One adult Alcocliara algarum had emerged by 

 October 9th, but the majority a])i)eared later. By October 2r)th about 7 

 had emerged; by November Sth there were over 20; and during the 

 remainder of November many more came out ; so that about 100 beetles 

 in all were bred from the puparia. One s])ecimen certainly emerged 

 between N(n'ember 29th and December 6th ; and there is some 

 doabt whether one or two more did not emerge some time between 

 December Gth and 20th, and effect their escape from the vessels. Willi 

 these exceptions, all emergences had ceased by November 29th. There 

 was thus a gap of about a fortnight between the emergence of the last 

 fiV and that of the first Aleocliara, and an interval of nearly two months 

 (mid-September to mid-November) between the times at which the Hies 

 and the beetles respectively wei'e emerging freely. 



Of all the beetles bred, only 3 emerged from puparia of Fi(cnmj/ia 

 (/rains ; the remainder were all from those of Coelopa p/lipes. The two 

 kinds of puparia are quite distinct from one another and from that of 

 Orygma luctiiosum. All three sorts have been determined by com- 

 parison with examples from which adult flies were bred, and which have 

 been preserved on the same cork-stages with the flies bred from them. 

 They are described below. 



After all the beetles had emerged, there was still a residue of 

 about 45 puparia of Goelopa and 5 of Fucomyia from which nothing had 

 been bred. Some 6 to 12 of these were oj^ened and found to contain 

 temains of dead flies and fly-nymphs, while one contained an Alcochara 



