174 LAMELLICOENIA. 



PHYTALUS. 



Phytalus, Erichson, Naturg. Ins. Deutschl. iii. p. 658 (1848) ; Burmeister, Handb. der Ent. iv. 2, 

 p. 345 (1855) ; Lacordaire, Gen. Col. iii. p. 287 (1856). 



A genus distinguished from the following (Lachnosterna) only by the mode of denti- 

 tion of the tarsal claws, the usual inner tooth, which in Lachnosterna varies in position 

 from near the base to near the apex, being here apical, so that the claws are properly 

 termed fissile or cleft. The examination of a large series of species has proved the 

 correctness of Lacordaire's opinion that this character would eventually prove untenable, 

 for I find that every gradation exists between a typical Phytalus with cleft claws, and 

 the section of Lachnosterna in which the tooth is placed near the base. I retain the 

 genus, however, as a convenient group, in the belief that a division of the great genus 

 Lachnosterna into numerous genera will soon become indispensable, and that Phytalus 

 will probably then be retained under some restricted definition. 



I have not here restricted the genus to those species in which the inner or lower tooth 

 of the claw is equal in length and subparallel to the apical portion, but have found it 

 necessary to include in it a numerous group in which this tooth is more or less short 

 but nearly parallel, and others (P. pubicoUis, Blanch.) in which it is considerably deflexed 

 and divergent though always nearer the apex than in Lachnosterna. Even thus 

 modified, the fissile character of the claws applies strictly to the males only ; the females 

 in some species (e. g. P. obsoletus) having the lower tooth rather widely divergent, thus 

 approaching the form presented in Section IV. of Lachnosterna. In facies and in nearly 

 all points of structure on which genera are founded in the ' Ehizotroginse ' there is no 

 agreement among the species. For example, the number of antennal joints varies from 

 10 to 8, the intermediate joints varying in relative length, and the leaflets of the club 

 vary in number in the males from 3 to 5 ; the lower spur of the hind tibiae, generally 

 articulated, is in some species connate ; the mandibles are visible or not in repose; and 

 the clypeus is of the most diverse formation. But it must be added that no better 

 result follows in this instable series of forms when any other leading character is taken 

 as a basis for grouping. 



A score of species of Phytalus have been described. Like Lachnosterna it is found 

 in America and in South-eastern Asia ; but unlike that genus it appears to be scarcely 

 represented in temperate North America, where Lachnosterna abounds in species. 

 The genus is not mentioned by Leconte in his important work on the Melolonthidae 

 of the United States published in 1856 ; but I have seen specimens of a species, 

 apparently undescribed, from Arizona. 



