FAUNISTIC NOTES. 171 



Magelona. — Abundant throughout the whole of September, 1893. 

 On some days I counted the specimens seen — September 21st, 30; 

 22nd, 20 ; 23rd, 5 ; 25th, 50 ; 2Gth, 35 ; 27th, 38. On September 23rd 

 all the Polychaete larvoe were scarce, but meduste and other animals 

 did not show any visible decrease. In 1895, Magelona was not nearly 

 so abundant ; often only a few present, occasionally none seen. On 

 September 13th it was fairly abundant. 



Mitraria. — This appears to be a rare animal on the southern coast of 

 England. I only obtained three specimens on 31st August, 1895. Dr. 

 Fowler informs me that some were taken a few years ago at Plymouth, 

 but were not recorded in the journal. Vallentin (1891) records Mitraria 

 for Falmouth in July, 1890. 



Actinotrocha. — None seen during September, 1893. Very scarce in 

 1895 ; only a few specimens seen ; the last taken on September 19th. 



Rotifei-a. — Garstang (1894), p. 235, writes — "Apparently character- 

 istic of this period (September) are the clouds of pelagic Eotifers, 

 which may be occasionally taken." I cannot find any references to 

 Rotifers in my notes for 1893. Certainly none appeared during Sept., 

 1895, as I kept a special look out for the benefit of a friend.* 



Thalia democratica-mucronata. — Garstang (1894) states the nets were 

 crowded with Salps in June, 1893. I saw none during September, In 

 1895 a few specimens were taken on September 9th only. 



Doliolum tritonis. — In 1893 a few specimens were taken at the 

 beginning of September, but soon became scarce. One or two occa- 

 sionally taken at the end of the month. In 1895, Doliolum was 

 exceedingly abundant at the beginning of September. Often the 

 tow-nets were crowded with specimens. There was a gradual decrease 

 towards the end of the month. 



Tornaria. — None seen during September, 1893, but often taken in 

 1895. Fairly abundant at the beginning of September, and a few were 

 occasionally taken at the end of the month. This is the same species, 

 Tornaria Krohnii, which Bourne (1889) found at Plymouth in 1888, 

 during August and September.* 



Ami^ioxus. — A specimen taken in the tow-net on September 3rd, 

 1895, about 2 mm. in length, and another on September 7th, about 

 3 mm. in length. None seen during September, 1893. 



In some of the species the variation is great, as they are absent in 

 one year and abundant in the other. Little value, however, can be 

 attached to the slight differences in numbers, as a species may be 

 present every year, but owing to its scarcity escape the tow-net, which 

 after all only traverses through a very small portion of the sea, even in 



* Cf. Hodgson, infra, p. 176-7. — Ed. 



