NO. 10 MORPHOLOGY OF GNATHOTRICHUS SCHEDL 75 



and a few papillae. The galea is largely fused with the lacinia. Dis- 

 tally a rather shallow fold indicates the separation of these two 

 sclerites. 



The setae of the maxillae have not been studied thoroughly enough 

 to decide if they are of taxonomic importance or not. In Den- 

 doctonus valons, no setae or punctures occur on the palpus and none 

 of them on the lacinia, according to the drawings published by Hop- 

 kins. On the other hand it was found that the setal arrangement of 



Table I. — Setae of the liead, nomenclature. 



Nomenclature of Dr. Russo Used on New nomenclature Used on 



Setole mediane-distalc 'I 



Setole submediane ^Frons Seta fronto-lateralis Frons. 



Setole lateral! J 



Setole basali Frons-epistoma . Seta epistomalis Fpistoma. 



Setole basali clypcali Clypeus Seta clypei Clypeus. 



Setole mediane distali "| 



Setole premediane Labrum Seta labralis Labrum. 



Setole sublaterali | 



Setole basali-laterali J „ 



beta verto-mediana / ,t , 



Seta verto-lateralis ) ^ ^'^'^^■ 



Setole laterale del vertice.."] 



Setole mediane LOcnae Seta geno-lateralis Genae. 



Setole basale | 



Setole interna del vertice. . J 



Setole della gena 1 



Setole mediane L Genae Seta geno-mediana Genae. 



Setole esterna f 



Setole basale Seta epicrano-lateralis Epicranium. 



Setole dorsali ll''"'^'^,'' 1^1^ mandibulae dorsalis. . . I Mandible. 



?ptnn siihlatenle basale Mandible Seta mandibulae lateralis..) 



iftola laSlTwipit^::: Stipes Seta stipitae maxillaris Stipes 



Setole mediane del palpifero. | Palpifer Seta palpiferae maxillaris Palpifer. 



Setole laterale del palpifero. I First joint of Seta palpo-raaxillaris 1° First joint of 



Setole palpiale palpus. _ _ _ palpus. 



Seta lacinio-maxillaris Laciniae. 



Setole mediane LSubmentum . . . Seta submento-lateralis Submentum. 



Setole subbasali ":..::..:: .7 S^j^ ^^^^. Mentum. 



Setole subbasali Mentum Seta labio palpif eris Palpifer of 



labium. 



Setole distale . 

 Setole mediane 



rSeta ligulae distalis. 



- Ligula < Seta ligulae mediana 



l^Seta ligulae basalis. 



Gn. materiarius Fitch is exactly the same as that of Chacloptcliiis 

 vcstitiis Fuchs, illustrated and described by Russo. 



Labium. — The labium (Lab) of the larva is very different in struc- 

 ture from that of the adult. Indications are that the labium of the 

 larva as well as that of the adult will become more and more im- 

 portant as the bearer of taxonomic characters in the Scolytidac. 



The submentum (SM) is present as a large sclerite and is trapezoid 

 in outline. The shape is more like that of Chaetoptdius vcstitus Fuchs. 

 It is slightly chitinized, laterally connected with the maxillae and 

 bears three pairs of setae (d), the same number and in a similar ar- 

 rangement as in Chactoptcl'ms vcstitus and Dendroctonus valcns. 

 Russo called these setae setole subbasale, setole mediane and setole 

 distale in order proceeding distad. The anterior margin of the sub- 

 6 



