24 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



circulation pipes. The tubicolous worms Spirorbis and 

 Serpula are found in every tank, the delicate little 

 Filigrana is represented by large and vigorous colonies, 

 Sabella has built its tube of mud and expanded its 

 beautiful crown of tentacles in various shady corners, and 

 colonies of encrusting Polyzoa attain quite a large size. 

 An incursion of the Nudibranch Dendronotus arborescens 

 occurred during the latter half of Tune. Small specimens, 

 ranging from § of an inch to 1 inch in length, 

 appeared in three of the wall tanks day after day. This 

 species is not common in Manx waters, indeed, Prof. 

 Herdman's record of its occurrence off Port St. Mary, in 

 vol. I. of the " Fauna of Liverpool Bay," seems to be the 

 only previous one. The occurrence of a full-grown 

 specimen, which still thrives in one of the table tanks, on 

 the submerged bottom of the harbour buoy, is, therefore, 

 worthy of note. Of the cluster of Sabella pavonia found 

 two years ago on the buoy, only one individual now 

 survives, but it is still adding to the length of its tube, 

 and appears to be in the prime of life. Our stock of 

 anemones undergoes little change from year to year, 

 except by the addition of a few choice specimens from the 

 fishing grounds, and which, it may be noted, are as 

 healthy in six inches depth of water as they were in twice 

 as many fathoms. 



Mr. F. II. Graveley, of Manchester University, 

 found a specimen of the Nudibranch Tritonia hombergi, 

 four inches long, on one of the blocks of the breakwater 

 one evening in July, and placed it in one of the table 

 tanks, in which some large specimens of Tad in 

 crassicornis have flourished for several years. Other 

 Nudibranchs, especially Arcliidoris tubevadata, had lived 

 for months in the same tank, and for some days the 

 Tritonia crawled about and expanded its beautiful cerata 



