of Buprestidse and Elateridse. 203 



scurus, sputator, Ampedus balteatus fifteen to eighteen ; Cardio- 

 phorus rufcollis, Agriotes marginatus twelve ; Cryptohypnus qua- 

 dripustulatus and Adrastus limbatus five. The oviducts are short, 

 and open through a short common duct into the under surface of 

 the vagina at a varying distance from its top; when filled with eggs, 

 their appearance is quadrangular. The eggs are rather small, 

 of short oval form : mature eggs, when taken out of the ovi- 

 ducts, measured in Agriotes marginatus 0*25 millim. in. length, 

 and 0"169 in width; in Limonius cylindricus 0'304 millim. by 

 0*179 millim.; in Diacanthus bipustulatus 0*309 millim. by 

 0*] 84 millim. ; in Diacanthus pectinicornis 0*429 by 0*232 millim. 

 The vagina is either long and tubiform, or short and club- 

 shaped. The tubiform type of vagina is, in places, of varying 

 thickness, strongly curved {Diacanthus pectinicornis) or sharply 

 bent at an angle {Melanotus castanipes, Limonius cylindricus, 

 Ampedus sanguineus, Diacanthus ceneus) ; when the oviducts join 

 the vagina far behind the end of the latter, it is winding or even 

 forms a spiral {Lacon murinus, Agriotes marginatus). The club- 

 shaped vagina is not often gradually widened towards the fore 

 end [Adrastus limbatus, Agriotes lineatus) ; more frequently the 

 thick fore end is sharply defined, and besides is constructed so 

 as to assume various forms {Cai'diophorus rujicollis, Cryptohypnus 

 quadripustulatus, Agriotes aterrimus, obscuru^, Diacanthus tessel- 

 latus, bipustulatus, Athous niger and subfuscus). The internal 

 surface of the vagina is furnished with a greater or smaller 

 number of spinulose plates of chitine, or with spines placed in 

 rows, or with both contrivances together, which do duty in the - 

 act of copulation as retaining instruments. The most frequent 

 combination is a couple of lateral plates {Cardiophorus ruficollis 

 and asellus, Lacon murinus, Agriotes aterrimus, lineatus, obscurus, 

 sputator, Diacanthus tessellatus, pectinicornis, sjcelandicus, bipus- 

 tulatus, Athous niger, rvficaudis, and subfusctis). The plates are of 

 difierent sizes, oblong, often with ribs and marginal teeth {Athous 

 niger and subfuscus) ; and in some cases a second pair of plates 

 over them are met with, which have spines on their inner margin 

 {Cardiophorus asellus, Diacanthus sjcelandicus and tessellatus) ; 

 in Lacon murinus there are, besides the pair of plates first men- 

 tioned, a number of long spines at the anterior extremity of the 

 vagina. When plates are wanting, the spines are so much the 

 more abundant {Agriotes marginatus, Ampedus sanguineus and 

 praustus, Diacanthus ceneus). 



The foremost dilated extremity of the vagina receives the 

 semen during the act of copulation, and thus serves as a kind of 

 bursa cop\ilati'ix, but is rarely separated by a constriction, 

 which, however, is the case in Cardiophorus rujicollis and asellus 

 and in Campy lus linearis. 



