54 



XV. Descriptions of three Species of the Genm 

 Phthiridium of Hermann, 



PHTHIRIDIUM. 



Phthiridium. Hermann^ Offers, Leach. 



Nycteribia. Latreille. 



Thorax depressus antice os in dorsum gerens : pedes 6 la- 

 terales ; feynora articulis 2, secundo longo compresso ; 

 tibice articulis 2, primo longiore compresso, secundo gra- 

 cili arcuato ; tarsi articulis 5, tribus primis (gradatim 

 brevioribus) brevibus, quarto longiore apicem versus 

 gradatim latiore, quinto breviore iingue didactylo in- 

 structo. 



Ahdomen'm utroque sexu 8-articulatum ; (FCEMlNiE ? seg- 

 mento primo dorsali producto, segmenta quatuor sequen- 

 tia tegente ; segmento ultimo utrinque stylo apice setigero 

 instructo : maris ? segmento ultimo majore.) 



Obs. Pectus postice productum recte truncatum; margine 

 setis rigidis brevibus atris dense ciliato. 



Habitant Phthiridia in Vespertilionidea inter pilos. 



This Genus was established in 1 804 by Hermann, who 

 named it Phthiridium, and in the following year it was ob- 

 served by Latreille, who called it Nycteribia. 



Its situation is extremely doubtful ; it was referred to the 

 Diptera by Latreille, who observes in a note that it may 

 probably be found hereafter to constitute a peculiar order 

 of insects. From the want of antennae, and from the con- 

 fluence of the head and thorax, I placed it amongst the 

 Arachnides, in a division by itself. Its mode of propaga- 



