XVI TERMITIDAE 389 



wood being eaten away and only a thin outer shell left intact. 

 A Termite, T. tenuis, was introduced in what manner is not 

 certainly known^ to the Island of St. Helena, and committed 

 such extensive ravages there that Jamestown, the capital, was 

 practically destroyed and new buildings had to be erected. Other 

 such cases are on record. Destructive species can sometimes be 

 destroyed by placing in the nests a portion of arsenicated food. 

 This is eaten by some individuals, who perish in consequence ; 

 and their dead bodies being consumed by their comrades, the colony 

 becomes checked if not exterminated. 



The number of described species of Termitidae does not much 

 exceed 100, but this is certainly only a small portion of those 

 existing, the total of which may probably reach 1000 species. 



Termitidae are classed by some naturalists with the Orthoptera, 

 and they have a great deal in common with some of the cursorial 

 division of that Order, more particularly Forficulidae and Blattidae; 

 but they differ from Orthoptera in the nature and form of the 

 wings. They are also classed by some, with a few other forms, as 

 a separate Order of Pseudo-Neuroptera called Corrodentia, but this 

 is not a very satisfactory course, as the Termitidae do not agree 

 closely with the forms associated with them, while the aggregate 

 so formed is far from being very distinct from other forms of 

 Neuroptera. On tho whole the best plan appears to be to treat the 

 Termitidae as forming a distinct family of the Order Neuroptera, 

 or to make it a distinct Order, as proposed by Grassi. Packard 

 now associates Termites in an Order with the biting-lice, and 

 calls it Platyptera. 



Fossil Termites. Termitidae were very abundant in Tertiary 

 times, and the genera appear to have been then much the same as 

 at present. In Mesozoic strata the remains of true Termitidae 

 apparently exist in the Lias in Europe, but farther back than 

 this the family has not been satisfactorily traced. It was formerly 

 supposed that Termitidae existed in the Carboniferous strata, but 

 this appears to be very doubtful ; and the fossil remains of that 

 epoch, which were presumed to be those of Termites, are now 

 referred by Scudder and others to the Neuropteroid division of the 

 Order Palaeodictyoptera, an Order which is formed entirely of 

 Palaeozoic fossil remains. 



^ According to Melliss, it is thought that the Insect may have been carried to 

 the island in a captured slave-ship. Melliss, St. Helena, 1875, p. 171. 



