( 567 ) 



is compelled to study liis specimens more intrinsically, and thereby enabled to 

 draw up a more adequate descriptiou. 



Now, it is obvions that the diagnosis of a geans would not teach us anything 

 more than the diagnosis of a species, if a genns were erected for every species. The 

 genus should remain a division above the species ; otherwise it would be a mere 

 encumbrance. Therefore we take it that one generic term would be sufficient ia 

 the family Poli/ctenidae, if the aifinities between the various species were pretty 

 equal. But that is not the case. The American forms, of which there appear to be 

 two, stand quite apart from all the Old- World species, and these latter again fall 

 iuto several natural groups, which is sufficient justification for dealing with the 

 separate branches of the family under different generic terms. Of some of those 

 branches we know so far only one species, which for that reason stands isolated in 

 the family. 



A key to the genera and species will be givea at the end of this revision. 



1. Genus : Poli/ctenes Gigl. (1864). 



Antennae longae, capitis angulos basales superantes, articulo secnndo clipei 

 latitudine minus qnam tertia parte breviore. Angulus basalis capitis non acute 

 productus, pins minusve obtusus. Elytra apice siugulatim fortissime rotundata 

 sine cteuidio. Genotypus: P. molossus Gigl. (1864) specim. matur. <?. 



Patria : Asia. 



Pnlycteues Gigl., Quart. Jourii. Mirr. Sci. (n.s.) iv. p. 25 (18G4) (type: .lfr,Zrtss)(.s-) ; Westw., Tlifsniir. 

 Oxon. p. 198 (1874) (partim) ; Waterh., Tm,i«. E,it. Soc. Land. p. 309 (1879) (partim) ; id., 

 I.e. p. S19 (1880) (partim) ; Speiser, Zuol. JaJirb., Suppl. vii. p. 37.3 (1904) (partim ; affinity ; 

 key to the species) : Kirkalily, Canad. Enlom. xxxviii. p. 375 (1906) (restricts PuUielenes to 

 molossus) ; Kellogg and Paine, Entoin. News xxi. p. 401 (1910) (verbal quot. of Kirkalrly's 

 synopsis) ; Horv., Ami. .\lus. Nat. Hung. 573 (1910) (key to the genera ; Euroctenes Kirk. syn. 

 with Pnli/clenes}, id., .Vem. I. Conr/res Intern. Kiilom. p. 2.01 (1911). 



Euroctenes Kirkaldy, Caiiad. Entom. xxxviii. p. 375 (1906) (type : lijrae). 



Giglioli's descriptions of the genus and species read as follows : — 



" Head large and prominent, elongated, obtuse, and rounded in front ; on its 

 posterior dorsal part is a j)lace of a nearly semicircular form, edged all round with 

 thick spines. On the sides of the fore part of the head are two three-jointed organs 

 (antennae f), bent backwards. A short neck-like piece joins the head to the thorax, 

 which is elongated and divided into two parts. 



" The prothorax is double the size of the metathorax, and is bordered posteriorly 

 witii a line of large spines, as those on the head of the male. 



" Abdomen of moderate size ; it enlarges distally, and is segmented. 



" Anterior legs rather short, the two following pairs rather long and slender. 



" Poli/ctenes molossus, Westwood and Giglioli (PI. Ib, tigs. 13 and 14). — This 

 remarkable creature inhabits the Chinese Molossus. 



" Body of a light colour, about j^hs of an inch in length. Head ronnded in front, 

 where a well-marked clipens, of a nearly semilunar shape, is divided oft'; just uudnr 

 its posterior angles are inserted the two antennae (?) ; over there insertion are five 

 large spines on each side ; these do not exist in the other specimen, which I take 

 to be a female. Each antenna consists of three rather thick cylindroid joints, the 

 basal one being the thickest ; a few hairs fringe their inner borders, and they are 

 bent backwards. Do they at all correspond to the organs whicli have been termed 

 palpi and maxilli m JS'i/cteribin''/ The integument of the head is finely striated ; 



