OF WASHINGTON. 443 



hooks on the abdominal legs was occasionally noted with Lepi- 

 dopterous larvas. Dr. Dyar replied that, so far, the only constant 

 character known to him was the possession of only a single ocel 

 lus on each side of the head with Tenthredinid larvae, whereas 

 with Lepidopterous larva? they are always multiple. He re 

 marked, however, that it would not surprise him to find excep 

 tions to this statement at any time. 



Dr. Howard exhibited lantern slides of 2 curious Coleopte 

 rous larvas taken from the recently published second part of Dr. 

 Sharp's " Insecta," namely, Cnemidotus ccesus and Silpha ob- 

 scura (originally figured by Schioedte) ; also of the pupa of 

 Aspidomorpha sp., all of these figures having reference to 

 previous discussions before the Society. He also exhibited the 

 beautiful plates illustrating the methods of destroying locusts 

 and crickets in Algeria, published in Kunckel's d'Herculais' re 

 port on invasions of locusts in Algeria by the French Government 

 in Algeria. 



Mr. Marlatt read a paper entitled " The Influence of Insu 

 lar Conditions in the Origination of New Species," taking as his 

 text the species of the Coccid genus Parlatoria and indicating 

 that in his opinion the two Ceylonese species, P. aonidiformis and 

 P. cingula, have been evolved from the only continental form 

 known to occur in Ceylon, namely, P. proteus, and showing 

 that the remarkable development of the two insular species is 

 simply an indication of the effect of isolation. Continental 

 forms, by means of constant inter-breeding, maintain a greater 

 uniformity of structure. 



The paper was discussed by Messrs. Gill, Ash mead, Vaughn, 

 Dyar and Busck, Dr. Dyar mentioning the unusual development 

 of the Hawaiian form of Vanessa, atalanta, Mr. Busck the diver 

 sity of the Tineids, described from West India Islands by Lord 

 Walsingham, Mr. Ashmead the curious development of the 

 genus Odynerus on the islands of Hawaii, and Dr. Gill, the ex 

 traordinary diversity of forms in the terrestrial mollusks in the 

 islands of Hawaii, Cuba, Jamaica, and Haiti, as compared with 

 the much lesser diversity in the same group on the continent of 

 North America. In regard to insects, Dr. Gill said it would be 

 interesting for entomologists in their studies of island faunas 

 to observe whether there was any tendency such as that which 

 has been noted in the birds in the line of reduction of wing area. 



