1840 British Association, 



type of a new genus, Ictis, allied to Acteonia, but differing in having dorsal tentacles 

 and in the absence of the groove and angles at the sides of the head. The animal is 

 limaciform. The head is scarcely angulated, and bears two linear tentacles on its dor- 

 sal aspect, behind and a little anterior to which are the eyes ; frons a little behind 

 the centre of the back. A single species, Ictis Cocksii, from Falmouth. The authors 

 propose to unite the genera, Elysia, Placobranchus, Acteonia, Chalidis, Limapontia, 

 and Ictis in a new order, characterized by the absence of specialized breathing organs 

 or other dorsal appendages, and for which they propose the name of Pellibranchiata. 



' Notice of Dredging Researches in Progress,' by Prof. E. Forbes. — A number of 

 specimens of remarkable British animals were laid on the table, preserved in a very 

 perfect condition by Mr. Goadby, who is at present accompanying Mr. M'Andrew on 

 a dredging voyage in the seas of the Zetlands and Hebrides. Mr. M'Andrew has 

 forwarded to the Meeting specimens of a living Terebratula, dredged off Skye; iden- 

 tical with the crag fossil, T. cistellula, of Mr. Searles Wood. A new Holothuria, dis- 

 covered by Mr. Gwynn Jeffreys, was also laid on the table. 



'On the Animal of Lepton squamosum,' by J. Alder. — The mantle of this 

 hitherto undescribed mollusk is very large, extending much beyond the shell, and is 

 fringed with filaments ; one of which is much longer than the rest. The mantle is 

 open, except before and behind ; where it forms a short siphon, with a single aperture. 

 The foot is very large, thick and tapering ; and has a disk like the foot of Nucula. It 

 forms a fine byssus. The branchial leaflets are two on each side. 



Mr. Waterhouse read a paper ' On the Geographical Distribution of the 

 Rodentia.' 



Mr. Westwood read a paper ' On the Habits of some Blind Insects.' 



The Prince of Canino read a paper ' On the Classification of the Testudinata.' — 

 The three principal groups into which he divided the whole of the species were, — 

 1. Testudinideae ; 2. Trionycideae ; 3. Chelonideae. 



Prof. Nillson read a paper ' On the Disappearance of certain Mammalia from 

 particular districts of the continent of Europe.' 



Mr. Peach announced some additions to the Cornish Fauna. The whole of the 

 species of Zoophytes found in the British islands are 224, of which 150 have been 

 found in Cornwall. He now added Corymorphasys nutans. In shells he had found 

 Lepton squamosum, Pleurotoma teres — in other departments, Planaria vittata, Onis- 

 cus ceruleatus. He also exhibited specimens of Botrylli, preserved in Canada bal- 

 sam, with all the colours perfect ; also the nidus of the Gurmellus, attached to the 

 under-side of stones found in Fowey Harbour. 



Mr. Westwood stated that Oniscus ceruleatus was an interesting discovery, and 

 described its structure, and drew particular attention to the enormous development of 

 the thoracic segments. — Mr. Charlesworth inquired the particulars of the finding 

 Lepton squamosum, as this had been hitherto regarded as an extinct species, belong- 

 ing to the older Tertiaries. — Prof. E. Forbes drew attention to the Pleurotoma teres. 

 He had first dredged it in the iEgean ; it had since been found in Norway, by Prof. 

 Loven, and now in Cornwall. He believed it was always found in what he called the 

 glacial outliers of modern seas— those places he had recommended for cod-fishing. 



Mr. W. Thompson announced the discovery of species of Teredo, Limnoria, 

 Xylophaga and Chelura, in Ireland, all of which were found contributing to the de- 

 struction of a pier. 



A discussion followed the reading of this paper, on the mode in which the Mol- 



