THE JUMPING PLANT-LICE OR PSYLLID^ OP THE NEW WORLD. 137 



ently, intended for a substitute for CJiermes, as Kirkaldy contended, 

 but only to take in part of it. Since a type-species has been desig- 

 nated for Psylla since 1810 and since Passerini in 1865 designated an 

 Aphid species as the type of Chermes,^ it is impossible to consider 

 Psylla as a synonym of the latter. 



The genus has been redefined several times (see bibliography above), 

 and various species have been designated as type. The vaUd type, 

 however, is alni Linngeus, as set by Latreille. 



Foerster ('48: 67) has divided the original genus into many distinct 

 genera, most of which are still vahd. Franz Loew ('78 : 600) defined 

 Psylla as it is to-day regarded. It is a very large genus and its 

 members are subject to considerable variation, thereby rendering it 

 difficult to determine specific fines in many cases. 



SYNOPSIS OF SPECIES. 



a'. Antennse not over two and a half times as long as width of head (except sometimes 

 in hrevistigmata); length to tip of folded wings distinctly less than 5 mm. 

 6'. Antennae less than twice width of head, or at most not more than twice, 

 r'. Hind tibiae without spur at base,'' or if present very small and indistinct. 

 d}. Forceps of male not simple; wings clear, transparent, 

 e'. Male forceps very broad at base, abruptly constricted near base, thence 

 slender; anal valve long, sides subparallel; vertex only slightly emar- 



ginate in front at median line fibulata, new species. 



e^. Male forceps with posterior margin conspicuously sinuate, apical third 

 slender, acute; anal valve converging to tip; vertex more deeply 



emarginate in front sinuata, new species. 



e^. Male forceps converging to near apex, then abruptly broadened and 

 T-shaped; antennae less than one and a half times •width of head. 



parallela, new species. 

 (P. Forceps of male simple, sides subparallel or converging to apex; winga 

 usually more or less fumate or maculate, sometimes clear. 

 c'. Wings maculate on posterior and apical margins and along Cu to its furca- 

 tion; pterostigma short; female genital segment exceedingly short. 



maculata, new species. 

 «'. Wings not maculate but more or less fumate, or clear; pterostigma rather 

 long; female genital segment not exceedingly short. 



/'. Antennae scarcely longer than width of head hreviata Patch. 



/2. Antennae about one and a half to two times as long as width of head. 



g^. Body very small, less than 3 mm. to tip of folded wings; wings small. 



h^. Wings fumate in apical half, without spot at tip of clavus; genal 



cones separate at base and strongly divergent. 



i^ Forceps of male 0.30 mm. long or more, converging to a simple, 



acute tip, pubescent almost uniformly from base to tip; body 



dark minuta, new species. 



t^. Forceps of male 0.20 mm. or less, apex not simply pointed; 

 scarcely pubescent on distal half; body lighter in color. 



coryli Patch. 



• I do not know whether or not this was the earliest date at which the type of Chermes was set, but it 

 certainly was not set before ISIO. 



2 If the hind leg is cleared and mounted on a glass slide, and examined under high magnification, a spur 

 will be found on practically every species of the genus. The above key refers, however, to a lower magnifi- 

 cation and the specimen not mounted on a slide. ' 



