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VII. — Scottish Rotifers, collected by the Lake Survey (Supplement). 

 By James Murray. (With Two Plates.) 



(MS. received November 8, 1907. Read November 18, 1907. Issued separately February 10, 1908.) 



Introduction. 



In June 1906 there was published an account of the Rotifers collected in the 

 Scottish lochs up to that date (7). Many Rotifers had been observed during the 

 survey of the lakes which are not referred to in that paper, as they were not collected 

 actually in lakes. It is with the object of recording these species, and especially of 

 giving an account of some interesting forms previously unknown or imperfectly known,, 

 that this supplementary paper is written. These Rotifers were, almost without excep- 

 tion, collected from moss, and, as is always the case in these circumstances, the 

 Bdelloida greatly preponderated over the other orders. 



Lists are given of the species found in the various islands visited — North Uist, 

 Orkney, Shetland, — as an assistance to students of distribution, though there is little of 

 special interest in these lists. The list from North Uist contains none but very 

 common species, but in Orkney and Shetland there were a number of rare and interest- 

 ing species. 



Two animals have been found with sufficient frequency on mountain-tops to suggest 

 that they may be specially adapted to the climate of such situations. They are 

 Callidina cornigera and C. plicata, var. hirundinella. Both extend into the most 

 northerly lands — the former to Spitsbergen, the latter to both Spitsbergen and 

 Franz Josef Land. 



Rotifers of the Scottish Lochs — Additional Species. 



Since the previous list was issued (7), nine additional species have been observed in 

 our lakes, and one distinct variety : — 



Callidina tridens, Milne. Loch Tay ; St Mary's Loch. 



C. constricta, Dig. Frequent. 



C. musculosa, Milne. Loch Ness. 



Rotifer hapticus, Gosse. A stout brown animal with stout antenna, common in 

 Loch Ness, seems to answer sufficiently to Gosse's description. The heavy antenna, 

 narrowed towards the base, resembles that of Callidina armata, Murray (6). It is 

 placed very far forward on the head in the creeping attitude. It is terminated by 

 what appears to be a single seta, but may be a pencil of setae. Otherwise the animal 

 has a strong resemblance to R. macroceros, Gosse, and I have a suspicion that it is that 

 TRANS. ROY. SOC. EDIN., VOL. XLVI. PART I. (NO. 7). 27 ' 



