The Scottish Naturalist. 261 



3. Vaucheria synandra, Woron. — Oogonia globular, with an 

 elongated decurved (lateral) mouth. (Fig. 3). 



B. Piloboloidese. Antheridia not furnished with an inter- 

 vening chlorophyll cell, but only with the short empty cell, 

 (a.) Oogonia attached directly to the thallus. 



4. V. coronata, Nordst. — Oogonia crowned with several tubular 

 mouths • antheridia with one, or rarely two, lateral openings. 



(Fig- 4). 



5. V. intermedia, Nordst. — Oogonia nearly sessile, globular . 

 oospore globular ; antheridia numerous, obtuse at the apex. 



(Fig- 5)- 



6. V. sphcerospora, Nordst. — Oogonia globular, with an elon- 

 gated cylindrical base ; oospore spherical, antheridia acute at the 

 apex. (Fig. 6). 



Var. diotca, Rosenv. — Antheridia on distinct threads. (Fig. 6 a). 



7. V. piloboloides, Thur. — Oogonia globular, with an elongated 

 cylindrical base; oospore lens-shaped, not filling the upper portion 

 of the oogonium ; antheridia long, cylindrical, with one or two short 

 conical tubular openings on the side, and one on the apex. (Fig. 7). 



8. V. litorea, Hofm., Bangia Ag. — Dioicous, oogonia at the apex 

 of a curved branch, often containing between the oospore and the 

 thallus a chlorophyll cell, which often contains a brown pigment. 

 (Fig. 8). 



There are two other species which differ from the foregoing in 

 the di-poly-chotomous branching of the thallus, but their organs of 

 fructification are unknown ; these are V. tuberosa, A. Braun, and 

 V. trifurcata, Ktz. 



Dr. Nordstedt also characterises the following species, V. aversa, 

 Hass., V. omithocephala, Ag., V. pachyderma. Walz., V. sessilis, 

 D.C., V. geminata, Walz., V. hamata, Walz., V. terrestis, Lyngb. f 

 V. uncinata, Ktz., and V. Debaryana, Woron. ined. 



These are, however, not marine species, except V. hamaia, 

 which has been rarely found intermixed with V. Thuretii. But 

 this species is more frequently found inland, and, as it belongs to 

 the same section as the other terrestrial species, it need not be 

 described here. The following species have been detected in this 

 country by Dr. Nordstedt : — 



V. Thuretii, Woron. (Fig. 2). Portree, Skye ; Brough. near 

 Hull ; Ballachulish ; Greenod, near Ulverstone ; in fruit, Aug., 

 1885. 



