424 Scientific Proceedings, Royal Dublin Society. 



base of hair. Diameter -0008 in. (pi. xix., fig. 3) ; [h] on basal 

 portion shorter, with bulbous base ; tapering ; very thick wall ; 

 scarcely tuberculate ; -0018 in. diameter (pi. xix., fig. 4). ^ 



Campanulace^. 



Campanula fragilis. — Hairs expanded on basal part of fila- 

 ment, rather long and slender (as compared with other species of 

 Campanula, in which hairs very similar, though varying greatly in 

 size, are found) ; somewhat flexuous ; wall strongly marked ; 

 generally obtuse, but sometimes acute ; very numerous. Diame- 

 ter -001, by -025 long. 



G. portenschlageana. — Hairs on base of filament obtuse ; short 

 and thicker than in C. fragilis ; resembling tentacles of actinia ; 

 wall thin. Diameter •0015--0020. 



C. medium. — Hairs on edge of filament very short and thick ; 

 somewhat papillate at top ; wall well marked ; closely packed. 

 Diameter •003--005 in. by -Ol-'OS long (pi. xix., fig. 5). 



OONVOLVULACE^. 



In all the members of this order which I have examined the 

 hairs are very characteristic, distributed generally over the fila- 

 ment ; multicellular, with a large terminal cell, which, as well as the 

 size of the hair, varies in different species; the terminal cell is 

 least marked in Calystegia sepium and C. sylvatica, reaching 

 its highest development in Ipomcea 2mrpurea and Convolvulus 

 mauritanicus. In Convolvulus tricolor, a non-scandent form, the 

 stamens are glabrous. 



Convolvulus mauritanicus. — Hairs comparatively slender ; rather 

 short ; terminating in a large piliform, obtusely triangular cell, 

 which is filled with granular protoplasm. Diameter •002--003. 

 (pL XX., fig. 2). 



Ipomcea learii. — Hairs very long and slender, composed of a 

 great number of exceedingly delicate cells ; terminal one oblong, 

 obtuse ; equal in transverse diameter to shaft of hair, and about 

 twice as long. Diameter '002 in. (pi. xx., fig. 5). Pollen spherical ; 



spiny. 



I. pmyurea. — Yery similar to /. learii, but larger in all its parts ; 

 terminal cell square. Diameter •002--003 in. (pi. xx., fig. 3). 



I. (?) species. — Also similar to I- purpurea-, terminal cell longer, 

 more slender, and pointed. Diameter -006 by '0015 (pi. xx., fig. 6). 



