SCIENCE-GOSSIP. 



22(j 



THE ESTUARY OF THE CROUCH. 

 By J. Henry Vanstone. 



T T is my purpose in this paper to call attention 

 to the fact that within a short distance of 

 London we have a good hunting-ground for a large 

 number of marine animals. I refer to the River 

 Crouch in Essex. For a long distance above 

 Burnham — the centre of the oyster fishery of the 

 Crouch — the water of the river is entirely salt, and 

 the same may be said of the water of the numerous 

 creeks and waterways in that district. Some three 

 or four years ago two papers appeared in the 

 " Essex Naturalist " giving the results of two 

 dredging excursions in this river. To the lists 

 formed by Messrs. Fitch and Crouch, the authors 

 of these papers, I have had the opportunity, during 

 July and August this year, of adding a number of 

 genera and species which came under my notice. 



During the latter end of July the river above 

 Burnham swarmed with Noctiluca miliaris, render- 

 ing the water at night beautifully phosphorescent. 



The Foraminifera I have not yet examined, but 

 Mr. Crouch records Peneroplis planatus, Lagena 

 vulgaris, var. striata, and a species of Miliolina. 



Amongst sponges occur Sycandra compressa, 

 S. ciliata, Leucosolenia botryoides, Chalina oculata, 

 Halichondria panicea, and H. coalita. 



The Hydrozoa are well represented by Sertularia 

 pumila, S. abietina, S.filicula, S. argentea, Halecium 

 halccinum, Obelia geniculates, Antenmilaria antennina, 

 Hydralmannia falcata, Clytia johnstoni (on the alga 

 Bryopsis plumosa), Tubularia indivisa, and Hydractinia 

 cchinata. Mr. Crouch recorded a Tubularian, 

 which he thought might be T. attenuata, a deep- 

 water species, but I have not been able to confirm 

 the capture. There also occur Aurelia aurita and 

 Rhizostoma cuvicri, Cyanea capillata, and Cydippc 

 pomiformis. 



Amongst Actinozoa there are present Actinia 

 equina, Hcliactis bellis, Alcyonium digitatum, and 

 Tealia crassicornis. The last-named is exceedingly 

 abundant near low-tide mark, and white and orange 

 varieties of Actinoloba dianthus are met with among 

 the debris of the oyster dredges. 



The Polyzoa so far met with are : Flustra 

 foliacea, Bugula avicularia, B. plumosa, Alcyonidium 

 gelatinosum (very common), Mem bra nip or a pilosa, 

 M. monostachys, M. Lacroixii, Membraniporella 

 melolontha, Bicellaria ciliata, Amathia lendigera, 

 Pedicellina gracilis, and a species of Avcnclla. 



Of the various worms there are Nereis pelagica, 

 Pectinarta belgica, Polynoc cirrata, Sabella penicillus 

 Aphrodite aculcata, and species of the genera Spio, 

 Filograna, and Ncphthys. 



The Echinodermata are represented by Solaster 

 papposa, Opliioglypha ciliata, 0. albida, Ophiothrix 



rosula, and U raster uibcns. I have not met with 

 Echinus miliaris, mentioned by Mr. Fitch, although 

 it is no doubt common. 



The Crustacea found are Pisa tetraodon, Hyas 

 arenarius, Portunus depurator, Carcinus mamas, 

 Eupagurus bemhardus, Crangon vulgaris, Stenorynchus 

 tenuirostris, Idotea emarginata (in great numbers on 

 Zostera marina), Hyperia latreillii, Balanus tintinna- 

 bulum. Mr. Fitch also found Pinnotheres pisum, 

 and Balanus porcatus. The Pantopoda consist of 

 Nymphon gracile, Pycnogonum littorale, and two rare 

 minute pantopods found by Mr. Crouch, Ammothea 

 Icevis and Anoplodactylus petiolatus. 



The list of Mollusca is rather a long one, and 

 has chiefly been worked out by Messrs. Fitch and 

 Crouch. Naturally in this river the oyster (Ostrea 

 edulis) stands first in importance. The fisherman 

 will, no doubt, place next the " tingle " [Purpura 

 lapillus), as it is the most inveterate enemy of the 

 oyster. There also occur Buccinum uudatum, Trochus 

 cinerarius, Nassa reticulata, Littorina littoralis. Tapes 

 pallustris, Cardium pygmevm, Crenella discors and 

 Crepidula fornicata (" crow-oyster," an importation 

 from North America). The above-mentioned 

 authors also record several chitons Velutina l&vigata, 

 Lacuna crassior, Hydrobia ventrosa, Pleurotoma ritfa, 

 Plwlas Candida, P. crispata, P. dactylus, Solen mar- 

 ginatus, Thracia papyracea, Nucula nucleus, Dentaliuiu 

 entalis, Modiolaria ■marmorata, M. nigra, Mytilits modi- 

 olus, Cardium echinatum,C. exiguum, Tapes aureus, Scrobi- 

 cnlaria alba, Myaarenaria, M. truncata, Telliua balthica. 

 Teredo navalis, Doris pilosa, D. tuberculata, Eolis 

 papulosa, E. drummondi, E. coronata, E. concinna (?), 

 Pluline aperta, Acera bullata, and Deto coronata. 



Two cephalopods are found in the Crouch, 

 Loligo forbesii, recorded by Mr. Crouch, but which I 

 have not seen, and Sepiola atlantiea, which came up 

 in large numbers in the trawl of Bridgemarsh 

 Island during my visit to the district. 



Of Tunicata, Molgula oculata, Ascidea virginea and 

 Styela grossitlaria are very common. I have several 

 specimens at present not identified. 



The surface life, with its swarms of amphipods 

 and copepods, its larval tunicates, worms and 

 crabs, still awaits investigation. Shore-collecting, 

 too, will yield some interesting results. 



In concluding this paper, I must express my 

 indebtedness to Philip Patmore, Esq., of Creeksea, 

 near Burnham, for the use of the oyster smack 

 "Britannia," and to Captain George Wilkinson 

 for his kindly assistance in obtaining the material 

 for this investigation. 



ii, Ardsley Terrace. Placquett Road, East Dulwich, 

 London, S.E. ; Oct. lyth, 1S94. 



