Mr. T. V. Wollaston on undescribed Madeiran Insects. 113 



Fig. 12. A barren stamen or petaloid body, more highly magnified; their 

 forms are variable. 



Fig. 13. Calyx of the male flower of Platanus occidentalis, showing the 

 bases of two stamens, with two of the bracteae left attached at 

 the base of the short pedicel. 



Fig. 14. The monadelphous bundle of stamens of Chloranthus inconspi- 

 cuus ; the scar shows the contracted base by which it is attached 

 to the rudimentary calyx on the anterior side of the ovary. 



Fig. 15. One of the half -anthers of Chloranthus inconspicuus cut off, and 

 showing the extent to which its connective is unattached to that 

 of the central anther. 



Fig. 16. A stamen of a Sarcandra seen laterally, showing one of the cells 

 only, which has an additional but imperfect half-anther pressing 

 on it so as to make it bifurcate at its lower part. 



Fig. 17. A female flower of Hedyosmum nutans, the calyx having been 

 partially separated to show the style and stigma. 



Fig. 18. A fruit of Hedyosmum glabrato-affinis crowned by the trifid calyx : 

 a, the anterior angle. 



Fig. 19. A transverse section of the ovary, more magnified, showing its 

 cavity, the calyx having been removed from it : a, the anterior 

 angle. In other species of this genus the same difference in the 

 placentae may be observed, although it is not so strongly marked ; 

 and there is also some difference in the anterior angle of the ovary. 



Fig. 20. An anther of Columellia oblonga, the cells being flattened so as to 

 show their convolutions and their relation to each other : the 

 lower end of the figure represents the external side of the anther, 

 its apex or most elevated part being near the centre towards the 

 opposite extremity, so that the four ends of the lobes meet rather 

 on the internal side. 



Fig. 21 . One of the cells of an anther of a Columellia, in which the sta- 

 men was accidentally smaller. 



Fig. 22. The half-anther of Bryonia dioica flattened sufficiently to show 

 all its convolutions : the convex side is external ; below is seen a 

 portion of the filament. 



Fig. 23. An ovary of a Lophophytum (L. Weddellii, or very near it) in 

 longitudinal section ; the dissepiment apparently quite free above. 



XII. — Brief Diagnostic Characters of undescribed Madeiran 

 Insects, By T.Vernon Wollaston, M.A., F.L.S. 



[With two Plates.] 



[Concluded from p. 28.] 



Ordo DIPTERA. 



(Sectio I. Proboscidea.) 



Genus Dilophus, Meig. 



Dilophus Madej'ce. PI. V. fig. 1. 



D. mas ater; alis fusco-cinereis.— Long. corp. 2, alar. 3 J- lin. 



Inhabits Madeira proper ; occurring in the sylvan districts 

 Ann. b; Mag. N, Hist, Ser.3. Vol.'i. 8 



