368 MR. ROBERT SHELFORD ON 



The geographical distribution of Prosoplecta is as follows : — 

 Eight of the species are found in the Philippine Islands, one in 

 Celebes, the remaining three in Batchian and Ceram. None 

 has yet been discovered in the Great Sunda Islands, so that the 

 distribution is discontinuous and serves to emphasize the view 

 that if the Philippines are to be regarded as a part of the Indo- 

 Malayan region, their separation from adjacent land is of very 

 great antiquity. The Philippine Islands constitute an area in 

 which insect mimicry hns attained great perfection. That is 

 shown not only by these wonderful cockroaches mimicking 

 Coleoptera, but Professor Poulton tells me that some of the most 

 wonderful examples of mimicry amongst butterflies are known 

 from these islands only, e. g. the distasteful Danaine genus Hestia 

 is mimicked very closely by a Satyrine and an Elymniine. 

 Again, the gorgeous little Curculionidse of the genus Pachy- 

 7-hyncJius are mimicked by other weevils, by Longicorns, by 

 Oetoniids, and by a cricket *. A comparative stvidy of mimetic 

 insects in geographically adjacent but zoologically distinct areas, 

 such as Borneo, the Philippines, and Celebes, is a piece of research 

 that would surely yield some very interesting results. 



I now give a synoptical key to the genus Prosoplecta with 

 descriptions of all the species known to me. It will be observed 

 that I have not always been able to pair a species of Prosoplecta 

 with a definite Coleopterous model, but I am pretty confident 

 that these models will eventually be found. I have not had 

 access to comprehensive collections of Philippine Coleoptera, and 

 so it is chiefly the Philippine Prosoplectae which for the present 

 I am not able to match. It is unfortunate that Semper's collec- 

 tion of Philippine Coleoptera is broken up and dispersed ; Stal 

 purchased his Orthoptera for the Stockholm Museum, and here 

 it was that I found four new species of Prosoplecta, but the 

 Coleoptera captui-ed at or about the same time and in the same 

 districts, I have not been able to trace. 



Key to the Species 0/ Prosoplecta. 



1. Less convex species. Tegmina with a smooth flat- 

 tened tubercle near the middle of the anal vein. 

 2. Pronotum piceous, margined all round with hj'a- 



line testaceous F. coccinella Sauss. 



2'. Pronotum bright rufous -P- hijpmictata 13r. 



1'. Verj' convex species. Tegmina without flattened 

 tubercles. 

 2. Ground colour of tegmina ochreous or rufous. 

 3. Tegmina maculate. 



4. Macular of tegmina piceous. 



5. Tegmina deeply punctate. (Pronotum with 



4maciilEe.) -P- irifaria Walk. 



* Semper in his ' Animal Life,' p. 390 (International Scientific Series, 1890) 

 gives figures of some of these mimetic insects, amongst them one with the legend 

 " Phoraspis (grasshopper) mimics a Coccinella." This is an error, for the Phoraspis 

 is a cockroach, apparently identical with Prosoplecta ligata Br. The species 

 described below as P. semperi is a much better mimic of the Coccmellid figured 

 by Semper than is P. ligata. Semper's figures (and error) are reproduced by 



Dr. Wallace in his ' Darwinism. 



