MARINE ZOOLOGY 



worm seen was met with only in the Heteronereis condition. The 

 first occasion was at Sheerness in the evening of ii May, 1882, when 

 a considerable number were swimming near the surface at a rate of 

 a few miles an hour. At first I thought they were small red fish, 

 and on catching some was astonished to find that they were worms. 

 Fortunately some have been preserved in the public museum at Sheffield, 

 and have been identified by Dr. E.J. Allen as the heteronereis o( Nereis 

 longissima. He informs me that Dr. Jonathan Herder observed a similar 

 display at Plymouth in April, 1865, tiut that nothing of the kind has 

 been seen there in more recent years. Those obtained at Plymouth 

 were 6 or 7 inches long, whereas those at Sheerness were only 4|. The 

 only other occasion on which I have seen any was in the evening of 9 

 September, 1889, at Queenborough, when the above-named species was 

 abundant. I never found this species in an unmodified state in any part of 

 the Queenborough district. Though I have been very anxious to obtain 

 other specimens, I never saw a single individual in the same or subse- 

 quent years ; and it thus appears that, as in the case of Nereis dumerilii 

 (Aud. and M. Edw.) found in Essex and Suffolk, the heteronereis is very 

 seldom seen, and then great numbers almost simultaneously appear, 

 swimming at the surface for a few hours, being a most striking spectacle. 

 About a mile above Queenborough the Swale makes a remarkably 

 sudden turn, which has caused the tidal currents to excavate a large hole, 

 at least 8 fathoms deep, which is about four times the depth of the water 

 above or below. This is the only locality in the Thames district where 

 I have dredged Dendronotus frondosus (Ascanius). Higher up I obtained 

 a number of fine specimens of the beautiful nudibranch 'EoUs papulosa 

 (Linn.) of which I never saw but one individual in Essex or Suffolk. 

 Acanthodoris pilosa (Miiller) is not uncommon in the Queenborough 

 district. One of the most striking peculiarities in the Swale near 

 Kingsferry is the great number of the common shore crab {Carcinus 

 mcenas) (Linn.), the spider crab [Stenorhynchus rostratus) and sponges, 

 chiefly Haiichondria panicea (Pallas), and the remarkably small number 

 of simple or compound ascidians : in fact, on the whole, this narrow 

 strait differs much from any other locality in the Thames district, 

 probably because it combines the shelter of an estuary with the salinity 

 of the more open water. Besides the above-named animals I have 

 found in the Queenborough district Tubular ia larynx (Ellis and Sol.), 

 T. indivisa, Solaster papposus (Fabr.), Ophiura ciliaris (Linn.), Ophiothrix 

 fragilis (O. F. Miiller), Caprella linearis, Idotea linearis and many excellent 

 specimens of Lerneonema sprattce, obtained from the whitebait caught in 

 such vast numbers. Appendicularians [Oikopleura sp.) occur in sievings of 

 the sea-water. 



Ramsgate. 



I have never examined any locality in which several species of 

 compound ascidians were seen to such great perfection as at Ramsgate 

 in the covered passages through which the water could be let out from 



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