362 



NATURAL HISTORY OF ARTHROPODS. 



develo]! muler favorable circumstances in a year, l)ut many of them require several 

 years to attain full gi-o\vth. 



The Elateriihe not only show their relationshij) to the LampyriJaj by anatomical 

 characters, but also by the ]iossession of luminous organs in a few species, these lumi- 

 nous organs being found in the larvre of a number of species, aud being long since 

 observed on the images of jPi/rophorus. 



Fig. 413. —Stages of an ElateriJ (Almis'i. 



The true Elatcriil;v have the posterior coxa- laminate, and tlie labrum visilile and 

 free. JMelanactcs piceiis is a very shining, black species, about one inch long, found 

 upon the Atlantic coast of North America as far north as Massachusetts. 31. niorio, 

 a somewhat smaller species with striate elytra, is found in the same regions. Larva', 

 suppo.sed to belong to J/clanactcs, are quite brilliantly lunnnous. 



It is, liowevei', to the genus Pi/rophorus, which contains aliout a hundred s]ieciesof 

 Elateridif, all from troiiical America, that we must turn for the most brilliant forms 

 of luminous insects. ]^i/rophoru.v noctiliiof.^, common in the West Indies and Brazil, 

 and in connnon with a few allied species called tlie cxciujo by the West Indians, is 

 from 1.50 to l.To inches long. Its color is a rusty brown, approaching black. Upon 

 each side of the prothora.v, near its basal angles, is a convex, oval lantern, which. 



