300 



Part III. — Seventh Annual Report 



December. 



As in the previous months Diatoms, spores of Algae and fragments of 

 the latter occurred especially in both surface and bottom-nets, only a few 

 being procured in the mid- water-net. 



In the surface-net various forms of Infusoria were procured on the 10th, 

 and in considerable numbers. They consisted of Ceratium tripos, C. 

 furca, and G. fusus. The same forms were also occasionally seen in the 

 bottom-nets, but in comparatively small numbers. The northern waters 

 differed chiefly from the southern, as in the estuary of the Thames, by the 

 absence of Noctiluca* 



A few Foraminifera, and a young sponge — probably Oculina — were 

 obtained in the bottom-net. 



The surface-net in December still presented many Pleurobrachice 

 from f inch downwards, along with ova. Circe rosea occurred sparingly, 

 but of somewhat larger size than formerly. A few examples of Tima 

 bairdH of medium size appeared occasionally. Moreover, Stomobrachiurrt 

 octocostatum was captured in this net in numbers at the commence- 

 ment of the month. 



In the mid-water-net Ccelenterate life was more varied. The ubiquitous 

 Pleurobracldce were in considerable numbers — and at no period throughout 

 the year were finer examples procured than in December — their size 

 ranging from J of an inch downward to i inch. The other Ctenophores 

 were an occasional Beroe about 1 \ inch, and a few Lesueuriai from -f inch 

 to an inch. Circe rosea again occurred in profusion from the beginning 

 to the end of the month, the large forms being about f- inch, the smaller 

 less than \ inch. The reproductive organs appeared to be well developed. 

 Tima bairdil reached its maximum size this month, as one fully 3 inches 

 across was captured. The reproductive organs at this time were advanced, 

 but not quite ripe. Stomobracliiurn octocostatum occurred occasionally, 

 some being about half an inch in vertical diameter. Lastly, two or 

 three examples of Tlxaumantias hemispluerica were also obtained. 



The bottom-net produced a few examples of Pleurobrachia and one or 

 two Lesueurice of moderate size. Pleurobrachia and Circe indeed occurred 

 in three out of four hauls. 



Contrary to what might have been anticipated one or two Plutei were 

 observed in the surface-net about the middle of December. In these the 

 arms were short and apparently atrophied or abnormal. The skeleton 

 was still visible, but no star-fish. 



In the surface-net a single Tomopteris J inch long was obtained. The 

 same form occurred in the mid- water-net occasionally, and from i inch to 

 § inch in length. In the bottom-net only bristles of Sabellaria and of 

 Nereis, with fragments of Polynoe, were taken. Such were probably swept 

 from the bottom by currents. The same bristles occurred in the tow-nets 

 at Sheerness-on-Sea. 



The Sagittse were remarkably numerous and of large size. In the 

 surface-net and in the bottom-net they appeared in similar proportions, 

 but not always in correspondence, thus the record of the surface-net on 

 the 5th, 13th, 14th, and 18th was 'numerous, few, many, few,' while in 

 the bottom-net it was ' few, many, many, few/ on the same dates. In the 

 mid-water-net they were especially abundant and large, ranging from f inch 

 to 1 inch, and the reproductive organs were well developed. They formed 

 a conspicuous element in the food of the various fishes at this season. 



During December the surface-uet showed a few Copepods, such as 



* For the condition of the waters at Sheerness-on-Sea, I am indebted to the notes 

 furnished by Mr Shrubsole. 



