100 REPORT— 1864. 



experiment. Tlie official reports, however, set aside tlie many doubts wliich hare 

 been expressed, showing very clearly that the temperature of the rivers in Tasmania 

 is suitable for the propapjation of the salmon. 



On the Genus Pteraspis. Bi/ E. R. Lankestee. 

 The author of this paper first reviewed the labours of previous writers on the 

 subject, remarking that little had been done of a very definite natm-e with regard 

 to the systematic arrangement or description of the species. He then minutely 

 characterized the various species of the genus, two of which, the Pteraspis Crouchii 

 and the P. Si/mondsi, were previously undescribed. He proposed also to divide the 

 genus Pteraspis, as it present exists, into three sub-genera, based upon the more or 

 less complex constitution of the cephalic buckler^ thus : — 



Pte7-asp)ides. 



Pteraspis. Shield separable into seven distinct pieces, viz. a central disk, an ante- 

 rior rostrum, two lateral orbital plates, tAvo lateral "coruua," and a posterior 

 spine. 

 Species, P. rostratus, Af/. ; P. Crouchii, Salter MS. S,- Lank. 

 Cyathaspis. Shield separable into four distinct pieces ; viz. a central disk produced 

 at one point into a short spine, an anterior rounded rostrum, and two large 

 closely attached lateral cornua. 

 Species, C. Banksii, Huxley ^- Salter ; C. Symondsii, Lanhester. 

 Scaphaspis. Shield not separable into distinct pieces, but oval, and with an acute 

 posterior spine. 

 ;^mes, S. Lloydii, ^(7. ; S. Lewisii, ^(7. ; S. trimcatus, J/wa;. ^ /Sa/^. ; S. Ludensis, 



Salter; S. Dunensis (?), Huxley. 

 The views advanced in this paper were based upon a very considerable amount 

 of evidence, in the form of specimens and drawings, some from the author's own 

 cabinet, some transferred to him by Professor Huxley. The discovery of the 

 scales of Pteraspis by the author, previously announced at the Geological Society, 

 was alluded to, and the geological range and palteontological relations of the genus 

 considered. 



Notice of a New British Rhizopod and some other Marine Animals. 



By W. A. Sanfokd. 



On the Turdus torquatus as observed in Devonshire. By Dr. Scott. 

 The Turdus torquatus pays an annual "visit to Devonshire, but it confines itself to 

 the tors and rocky valleys of Dartmoor. It lays four or five eggs, resembling those 

 of the Turdus merida, save that they are a little lighter in colour, and a little more 

 elongated in form. Its flight is darting and irregular, and, when on the wing, it 

 utters a chattering note of alarm ; but it has no prolonged song, like the sylvan 

 thrushes generally. It feeds chiefly on the Vaccinium Myrtillus ; but when these 

 are scarce it is seen feeding on the berries to be found in the hedgerows adjacent to 

 the moor. Its habits more nearly resemble those of the Petrocincla than those of 

 the true thrushes, and in Devon it is known by the name of the Rock-Ouzel. It 

 arrives in the end of April, breeds in June and July, and leaves in the beginning of 

 October. 



On the Significance of the Septa and Siphuncles of Cephalopod Shells. 

 By Haert Seelet, F.G.S. 

 " As the chambers are always empty, the animal must have moved foi-ward, 

 leaving a vacant space behind; so the question to be solved is. Why did the 

 creatiure always make the septa shut off" spaces which progressively enlarged ? In 

 certain gasteropod shells there is something analogous. Tlie genera Murex, Triton, 

 Manella, for instance, after making their shells uniformly for a third or half of a 

 whorl, then begin thickening the lip into a varix. In other genera, as BuUmits, 



