INTRODUCTION. vil 



were, in Central America, fully one-half of the described species being found there, many 

 of these not extending beyond our limits. Semiotus, too, though poor in species, is 

 represented by some of the largest known members of the genus, several of these (like 

 Chaleolepidius) being very much in evidence in the forest clearings in the low country. 



Attention has already been called to the excessive rarity of the males of the genera 

 Chaleolepidius and Semiotus, and to the fact that the sexual characters of the last- 

 mentioned genus have been misunderstood, the supposed males being really females. 

 The extraordinary geographical distribution of Meristhus scohinula — China, Southern 

 United States, and Central America, — doubted by Dr. Candeze, has been verified, but 

 no explanation can be offered to account for it. The wide distribution in America of 

 Hemirliipus fascicularis and Orthostethus infuse atus — both large and conspicuous 

 insects — is also worthy of comment. 



To summarize, there is little to distinguish the Elateridse of Central America from 

 those of Tropical South America, most of the genera being common to both regions, 

 and the endemic genera exceedingly few in number; but they differ greatly from those 

 of America north of Mexico, as shown by the larger North-American genera, Corymbites 

 having eighty, Elater forty-nine, Melanotics forty-four, and Limonius thirty-one 

 species respectively — the numbers for Central America being one, one, five, and two, — 

 and the absence in Central America of such genera as Melanactes, Sericosomus, 

 Pityobius, &c. North America, moreover, has only one Pyrophorus and three 

 Ischiodontus, and no Semiotus. My labours on this Family have been greatly 

 facilitated by free access to the very extensive collection of Elateridae formed by the 

 late E. W. Janson ; and also by the assistance of Dr. Candeze, the well-known veteran 

 specialist in this group, who has been kind enough to lend the types of the whole of 

 the described Central-American Elateridae now in his possession. 



The Cebrionida? is a Family containing but few species, mostly belonging to two 

 genera, Cebrio and Scaptolenus, chiefly remarkable from the great rarity of the females, 

 which are either apterous or have abbreviated wings, the males, too, of many of them 

 being rarely found. One genus only, Scaptolenus, is represented in Central America ; 

 twenty-nine species, with nine new, are enumerated. It has not yet been recorded 

 from South America. 



The Rhipidoceridee is another Family of limited extent, and in which also the 

 females are rarely met with. Fourteen species, belonging to three genera, are recorded 

 from Central America, one genus and eleven species being treated as new. Callirrhipis 



