Anatomy of the MaJe Genital Tube in Coleoi-)tera. 517 



lateral lobes joined together on their ventral aspects and forming a 

 large plate ; the median distal portion of the plate projecting between 

 the distal ends of the lateral lobes as a free process, truncate at 

 tip (6). No differentiated internal sac. 



In this species there is a distinct abdominal plate between the 

 anus and aedeagus (Iv), which we think must be the last ventral 

 sclerite of the body. 



Tarphiomimiis indentatus is of a similar type (PI. LVII fig. 93). 



Aulonium lidentatum (PI. LVII figs. 91, 91 f^). 



Median lobe large, somewhat flattened ; median orifice near tip 

 on ventral face. Tegmen formed of a large basal-piece, chitinous on 

 ventral and membranous on dorsal aspect, and a large piece, formed 

 of the lateral lobes consolidated together to near their tips, on the 

 ventral face. 



Derdaphrus ignavus (PL LVII figs. 94, 94a). 



Median lobe long, slender and tubular, with median orifice at tip 

 on dorsal side, median foramen at base, which is slightly swollen. 

 Tegmen consisting of two short, broad lateral lobes, rounded at tip 

 and bearing a strong curved spine at base, between which the median 

 lobe passes. Basal-piece short, projecting as two short struts (a) at 

 base. Internal sac imdifferentiated. 



Some other species (which cannot be determined l)Ut are not 

 D. piceus, the type of the genus) are of the same construction with 

 slight difference in details. 



Cerylou histcroides (PI. LVII fig. 95). 



The aedeagus consists of a long, tubular median lobe, swollen at 

 its apex, across which is the median orifice ; and a small ring- 

 shaped tegmen articulated at the base of the median lobe. Internal 

 sac complex. 



Obs. — There is great diversity among the few forms 

 of Colydiidac v^e have examined. 



We might perhaps associate Enarsus and Aulonium, 

 though there is much difference between them. Enarsus 

 is one of the connecting links of the trilobe aedeagus with 

 the sheath-forms (Trogositidae, etc.) that we have at 

 present placed in Cucujoidea. We have therefore in our 

 table also given this genus a place in Byrrhoidea, 

 Atdonium is more definitely Trogositoid, 



Deretaphms is not thoroughly elucidated. There may 



