244 Rev. F. D. Morice on Andrena taraxaci, etc. 



Two of them are well-known species, others have only 

 recently been detected, and two, I believe, are hitherto 

 undescribed. 



In Plate VII I show this segment (equally magnified) 

 in each of these species in three aspects, ventral (Figs. 1, 

 2, etc.), dorsal (Fig. 1«, etc.), and lateral (Fig. 16, etc.); 

 and I will now, after a very short general survey of the 

 characters they exhibit, attempt to tabulate them in a 

 synoptic form. Next, as far as I know them, I will give a 

 synopsis for distinguishing the females. And 1 will 

 conclude with some further notes on the insects of this 

 group, clearing up, as I hope, some confusions in the 

 synonymy, on the common characters of the group and its 

 probable limits, and with descriptions of the two new 

 species. 



Looking at the segments (Plate VII) as a whole it is 

 clear to me that Figs. 6, 7, 8, and 9 make a very definite 

 sub-group united {inter alia) by the highly paradoxical 

 tooth-like dilatations on each side of the " geniculation " 

 (see the preceding paper). These dilatations appear in an 

 inchoate or rudimentary form in Figs, 10« and 11a also, 

 while they are entirely wanting in my first six figures. 

 Again, Figs. 1 and 2 are united by («) the trumpet-like 

 dilatation of their " apical processes," (6) the appearance 

 (explained in the preceding paper) of a strong subapical 

 tooth on the dorsal (naked) side (Figs. Ih, 2h), and (c) by 

 the " shouldered " outline and violent constriction of their 

 " basal plates " towards the origin of the " processes." Figs. 

 3 and 4 are very like each other, but difi'er enough in their 

 proportions to be specifically distinguished : and Fig. 5, 

 while nearer to Figs. 3 and 4 than to any of the others, is 

 separable from them at a glance. Between Figs. 10 and 

 11 I can see no specific difference, and I believe that the 

 insects from which they were drawn are varieties of a single 

 species. 



The figures were drawn with camera lucida, and. to 

 economise space, show the " basal plate " in the ventral 

 aspect only. 



Synopsis of the Valvule. Ventrales. 



Process on each side of its geniculatiou (base of the 



pilosity) simple ... ... ... ... 1. 



Process on each side of its geniculation (base of the 



pilosity) evidently dilated 5. 



