the Freshwater Algae of Africa. 



603 



Samples 12, 13, 14. 



Long, et lat., 20 //. 



Forma minuta I Pig. fc3, F). 



Samples 14, 15. 



Long, et lat.. 5-6 //. 



These small individuals occurred in enormous numbers, especially in 

 sample 14. Most of the testae of this form display a small pore 

 situated at the end, opposite to that at which the usual aperture 

 occurs (Fig. 43, F). It is very difficult to arrive at any conclusion as 

 to the exact nature of this pore. 



2. Trachelomonas radiosa, n. sp. (Fig. 43, A-D.) 



Fig. 4.3. — A — D. Trachelomonas radiosa, n.sp.' A. Seenfrom theailterior end. 

 B. Seen from the posterior end. C and D. Side views ( ]>, optical section). 

 E. T. oblonga, Lemra. F. T. volvocina, Ehrenb., f. minuta. <•. V. incerta, 

 Lemm., var. minor, nov. var. All figures x 960. 



Testa spliaerica polis deplanatis, rubiginosa, paullo latior quam 

 Longa ; porus flagelli parvus, collari brevi extus vel intus paullo promi 

 nenti, 2 2 - 5 fx alto, circumdatus. Membrana incrassata, in partem 

 anteriorem testae cum cost is longitudinalibus ca. 12 subirregulariter 

 dispositis (prope mediam testam evanescentibus) et in totam super- 

 ticiem punctis minutis uumerosis praedita. Flagellum crassum, paullo 

 longius quam testa. Content us ignotus. 



Loug , 17—18 /x ; lat., 2U//.. 



Sample 14. 



This species at firs) sight hears a strong resemblance to a T. volvo- 

 cina, with flattened poles, but its characteristic markings distinguish 

 it at once on closer scrutiny. Viewed from either end the shape is 

 circular (Fig. 43, A, B), but in a side-view the flattening of the poles 

 is quite distinct ( Pig. 43, C, 1>). Starting from the collar at the front 



