18 Mr. J. O. Westwood's Observations 



II. Observations upon the Hemipterous Insects composing 

 the Genus Syrtis of Fabricius, or the Family Phymatites 

 of Laporte, with a Monograph of the Genus Macroce- 

 phalus. By J. O. Westwood. 



[Read October 2, 1837.] 



The very singular structure of the insects composing this little 

 group, combined vvitli the very great rarity of the species of which 

 the genus Macrocephalus is composed, will, I am sure, be deemed 

 considerations of sufficient interest for bespeaking the attention of 

 the Entomological Society to a few observations upon the group 

 itself, and to a description of the species composing the genus 

 in question ; of which I have hitherto seen no specimens except 

 in the Collections of the Royal Museums of Berlin and Paris, 

 and those in my own cabinet, all of the latter having evidently, 

 from their labels, been obtained from Mr. Abbot of Georgia, of 

 which country they are natives. 



The earliest notices of this group are to be found in the works 

 of Linnseus, Geoffroy, Sulzer, De Geer, and Schellenberg, wherein 

 two of the species were described as species of the genus Cimex, 

 and rudely figured. Swederus however first proposed the generic 

 separation of some of these insects having a very large scutellum 

 from the great genus Cimex, under the name of Macrocephalus, in 

 the Swedish Transactions for 1787; having for its type the M. 

 cimicoides, an inhabitant of the southern states of North America, 

 and which, together with other insects observed in the cabinets of 

 Drury and other English Entomologists during a visit to England, 

 he described on his return to Sweden in 1787. In 1802, Latreille 

 proposed another genus, Phymata, in the third volume of his 

 Histoire Naturelle, &c., the type being the European species pre- 

 viously described by Fabricius as an Acanthia (A. crassipes). 



In the following year, 1803, Fabricius, unacquainted with the 

 establishment of the geneva. Macrocephalus and Phymata, described 

 the genus Syrtis in his Systema Rhyngotorum, into which he intro- 

 duced the species of both genera, Macrocephalus and Phymata. 

 It is essential, however, to observe the precise manner in which 

 he treated the species of this new genus, as it affords another 

 instance of the necessity for the adoption of the principle which I 

 have elsewhere endeavoured to illustrate, namely, that it is essen- 

 tial in subdividing any old and extensive genus to retain the old 

 generic name for that particular species which can be clearly 

 shown to have been the insect which the author of the old genus 



