MARINE ZOOLOGY 



V. NEMATODA (?) 



Nectonema (?). I have seen only one specimen, 

 which was caught when swimming near the 

 surface in Harwich Harbour. It is white, 

 Jijin. long, and about ^V '"■ wide from 



end to end. When examined with a 

 microscope it is seen to be full of eggs, and 

 is probably a fish parasite which escaped 

 from its host when mature 



VI. ANNELIDA 



I. POLYCHAETA 



Aphrodita aculeata, Linn. Some years ago I often 

 dredged this in the Stour off Harwich, but 

 I have not obtained it there recently. It 

 is much more abundant in the Wallet 



Lep'idonotus squamatus, Linn. This occurs in most 

 localities, but not in great numbers 



Nereis diversicolor, Milll. Common in the various 

 estuaries in the mud left dry at low water, and 

 in 1901 was very abundant in the Orwell 

 at Pinmill not much below high-water mark. 

 Some specimens are red, from the amount 

 of h.iemoglobin, others are pale, and some 

 deeply coloured by a peculiar green pigment 



■ — cuhrifera, Grube. In 1901 this was com- 

 mon in the sandy mud near low-water off 

 Harwich. It can be distinguished at once 

 from the other species by its peculiar man- 

 ner of swimming 



— pelagtca, Linn. Before 1 901 this was com- 



mon, and of large size outside Harwich 

 Harbour, being dredged up with masses of 

 the sandy tubes of Sabellaria spinulosa, but in 

 1 90 1 this material had been bro'cen up. I 

 found only a few small specimens or none 

 at all. I have also occasionally dredged it 

 in the Aide off Orford 



— kngissima. In 1901 I obtained from the mud 



near Pinmill the only specimen of by far 

 the largest Nereis I have ever found irt the 

 south-east of England. It is 7 in. long, and 

 above \ in. thick, and agrees with specimens 

 collected near Queenborough in the Hete- 

 ronereis collection identified by Dr. E. J. 

 Allen. It was so strong and active that it 

 broke itself in two when put into diluted 

 formalin, which I do not remember to 

 have happened in the case of any other 

 Nereis. On 24 May 1889, when sailing up 

 the Orwell, I saw several specimens of a 

 large Heteronereis swimming near the surface 

 which may have belonged to this species, but 

 none were collected and properly examined 



— dumerilii, Aud. & M. Edw. Probably com- 



mon in many places, but often lost out of 

 the dredge. The best specimens I ever 

 obtained were from an old buoy near Pin- 

 mill. When kept alive they soon built a 

 semi-transparent branching tube open at 

 both ends, from which they came out to 

 feed on Ulva latissima, and went back again. 

 One which I had kept alive for a consider- 

 able time laid in a few minutes eggs carefully 

 estimated at about 10,000, and had not 



I. POLYCHAETA (f«./.) 



passed into the Heteronereis condition. I 

 never found it completely changed except 

 when swimming near the surface. Though 

 I have lived so long on the estuaries of 

 Suffolk I saw this only on one occasion, 

 which was in the early morning of 16 July 

 1898, when they were so numerous for a 

 few hours in Harwich Harbour that there 

 were probably something like a million. 

 All those caught appear to be males or females 

 containing no ova. The maximum size 

 was about i \ in long, which is about one 

 half that of those found at Pinmill, some of 

 which contain ova 



Nephthys hombergii, Cuvier. I have obtained many 

 from the mud of the Orwell, and it is fairly 

 common in the other estuaries of Suffolk. 

 It varies considerably in colour, being more 

 or less red or brown 



— caeca, Fabr. I have found a few specimens 

 off Harwich and near Pinmill, but it is ytxy 

 much more rare than the other species 



Phyllodoce maculata, Mull. Occurs in the sandy 

 mud near low-water level off Harwich, but 

 is comparatively rare 



Syllis armillaris. Mull. Obtained from material 

 dredged in the Stour off Harwich, and may 

 be common, but often lost on account of its 

 small size. It is interesting from the 

 manner in which it multiplies by the forma- 

 tion of one or more heads in the length of 

 the body and subsequent division 



Nerine foHosa, Aud. and M. Edw. I have found 

 this in the mud of the Orwell, but it appears 

 to be rare 



Scolopus armiger, O. F. Muller. All my preserved 

 specimens were collected in Essex, but I 

 think it very probable that I have found it 

 in the sandy mud off Harwich 



Cirralu/us cirratus. Malm. Though rare elsewhere 

 in the district of the Thames estuary, and 

 I have not found it in any other place in 

 Suffolk, it was most remarkably abundant 

 in 1900 and 1901 in the mudbanks of the 

 Orwell near Pinmill, so that hundreds could 

 be collected in a short time. Though most 

 of them seem to me to be somewhat smaller 

 than they were about 1890, the species 

 has so greatly increased in numbers that it 

 has probably driven away many other animals 

 that at one time were common. Most of 

 the specimens are of dark colour, but others 

 pale. One that I kept alive laid in a short time 



91 



