72 REPORT — 1841. 



character, possess little nutriment fit for the nourishment of the fish. Most alpine 

 streams are composed of melted snow or rain- water, and possess few constituents that 

 will afford nutriment to fish, more especially the eel, and thus their absence may he 

 easily accounted for. The same remarks apply to the Rhine, which is comjiletely al- 

 pine in its character till it reaches the Moselle. The author announced that Prof. 

 Heckel was about to publish a work on the freshwater fishes of Austria, which would 

 contain some new genera and a large number of new species. 



Dr. T. Thomson exhibited two living specimens of Lepidosiren which he had taken 

 in Macartney Island, on the Upper Gambia. They were found lying imbedded 

 in a hole in the rock, from which they could only be removed by a hammer. They 

 were almost covered with a coat of mud, which one of the specimens still retained. 



Dr. Tripe exhibited some specimens of Pontia. In their marking they resembled 

 P. Rapm and P. Napi, but were very much smaller. In some points of structure 

 they differed from the large species. The club of the antennie was less abrupt, and 

 the wings were more square in their form. They had only been found during very 

 hot and dry summers in one locality near Whitsand Bay, In wet seasons they were 

 never seen. They were mostly found feeding on the blackberry. 



On two remarkable Marine Invertebrata inhabiting the JEgean Sea. 

 By E. Forbes, F.L.S. 



These animals were taken in the harbour of Nousa, in the island of Paros, which is 

 extremely rich in marine productions. The depth of the bay is generally from seven 

 to ten fathoms ; the bottom sand and weed. The animals differ according to bottom 

 and depth. Amongst the sandy heaps at the bottom of this bay are two new animals. 

 The first a zoophyte of the family ActiniadcB, which is free and vermiform, and which 

 lives in a tube of its own construction, — a combination of characters hitherto unnoticed 

 among the helianthoid polypes. The second is a tubicolar annelide, which lives in a 

 strong gelatinous tube, bearing a remarkable analogy to the sac of certain Entozoa. 

 These two animals are noticed together, as in each case the peculiarity of the organi- 

 zation and habits is the result of a similar adaptation of form, in two very distant tribes, 

 to a similar locality. In the absence of works of reference, the author abstained from 

 giving names to these animals, although he believed them to be new, both generically 

 and specifically. 



On Deposits in Springs, Rivers, and Lakes, from the existence of Infusoria. 



By E. Lankester, M.D. 



Dr. Lankester communicated some additional observations on the existence of or- 

 ganic beings in mineral waters. He had found the Conferva nivea of Dillwyn in the 

 sulphur spring on the river Leith near Edinburgh. He had also found it in the wells of 

 Moffat in Dumfries-shire, Gilsland in Northumberland, and Middleton and Croft in 

 Yorkshire. At Moffat he found great quantities of the substance called glairine, and 

 was convinced of its organic nature. At Moffat also he found a pink deposit in the 

 drains outside the wells, and on submitting it to the action of the microscope, he found 

 that it was produced by an animalcule, but much smaller in size than those which pro- 

 duced the coloured sediments of Harrowgate and Askern. It had the characters of a 

 Monas, and was not more than TTws-'h of an inch in diameter. 



On Cecidomyia Tritici. By Prof. Henslow, F.R.S. 



Prof. Henslow invited the co-operation of members in his attempts at perfecting 

 the natural history of the Wheat-Midge {Cecidomyia Tritici). He stated that he had 

 not been able to breed a single fly from many hundred larva; which he had procured 

 from the barns in his neighbourhood, during the winter months, by sifting the chaff 

 immediately after the corn had been dressed. Mr. Curtis had been equally unsuc- 

 cessful. The inquiry to which he was anxious to direct the attention of naturalists 

 was, whether the flics which appear in myriads during the first Aveek of June and then 

 deposit their eggs in the ears of wheat, have proceeded from larvae which had entered 

 the ground, and had there assumed the pupa state, or from larvae which were housed 



I 



