402 Transactions of the Society. 



this preserved material at home the following ten species of Rotifers 

 were found — 



Triarthra longiseta Ehrbg. Few. 



Diurclla stylata Eyferth. „ 



Metopidia oxysternum Gosse. „ 



Tctramastix opoliensis Zacliarias. Three specimens. 



Pompholyx complanata Gosse. Many. 



Brachionus pala var. dorcas Gosse. Abundant. 



„ angularis Gosse. Few. 



Anurwa aculcata var. valga Ehrbg. Many. 



„ cochlearis {forma micracantha) Gosse-Lauterborn. 

 Pcdalion mirum Hudson. Abundant. 



It was interesting to come across Pedalion mirum in this locality, 

 but the most extraordinary find was Tctramastix opoliensis, a species 

 which I had never yet seen, and Which has. as far as I know, only 

 been found once before by Dr. Zacharias in 1897 (25), who dis- 

 covered it in preserved plankton material from the Oder, near 

 Oppeln, in Upper Silesia, Germany. The loricate body is elongate, 

 spindle-shaped, slightly compressed laterally, with two long anterior 

 and two posterior spines of unequal sizes. The two anterior spines 

 are similar in shape, both starting from a triangular base, and 

 diverging, but the right spine is nearly twice as long as that on 

 the left side. Posteriorly the large spine is median, dorsal in 

 position, and much stouter at its base than the shorter and ven- 

 trally situated spine ; these two spines originate close together, 

 dorso-ventrally (not side by side, laterally, as figured by Dr. 

 Zacharias), and run parallel to each other. One specimen carried 

 an egg, attached posteriorly to the ventral side. Dr. Zacharias 

 figures a large median eye, but no eye can be detected in my 

 contracted and mounted specimens. PI. XY. fig. 2, is a good 

 representation of this animal drawn by Mr. F. R. Dixon-Nuttall. 



The following sizes were obtained from my largest specimen : 

 size of body alone, 204 //. (y-^- 5 in.); of large anterior spine, 374 /j, 

 (g ! g in.) ; of large posterior spine, 272 /j, (^ in.) ; total, 8c0 fi (o 1 ^ in.). 



All I could do at the time of collecting was to preserve the 

 material in formalin, without even looking at it, so that this 

 Rotifer has never yet been seen or examined in the living state, 

 and its mode of progression through the water is not known, 

 though it may fairly be guessed that it swims in similar fashion 

 to Notholca longispina. 



On the Monday morning, September 11, we started in our 

 special trains for the Victoria Falls, situated at a distance of 282 

 miles north-west of Bulawayo. Travelling through a forest region, 

 in which the trees were without foliage, having learned to shed 

 their leaves during the dry season, though the temperature was 

 quite warm, we reached a station called Igusi, I think, where the 



