308 MEMORANDA. 



fitted Avitli a disc of tliin glass, is gimbled on to an arm that 

 rotates upon a centre pin, which arm is acted on by a mill- 



•*"«:c*>v 



head-screw to secure compression by leverage in the ordinary 

 way. If both the upper and under side of an object are to be 

 examined, two pins are to be screwed into the ends of the 

 base plate, and these, with the pin that stops the arm, (to 

 secure the compression, being central with the aperture in the 

 base-plate), form a tripod stand, so as to allow of the instru- 

 ment being turned over, and either side being placed on the 

 stage of the microscope at pleasure. By this arrangement it 

 will be seen that any portion of a 3 by 1 glass slide can, by 

 traversing, be brought under the compression, and that every 

 movement and requirement is provided for. One of these 

 instruments Vidll be found'in my collection, in Class XIII, at 

 the International Exhibition. — Samuel Highley, 70, Dean 

 Street, Soho Square, W. 



Supplementary !N"ote on the Reproduction, of Thaumantias.— 

 Since my note on the reproduction of Thaumantias was 

 written, each of the secondary polyps of the zoophytes in the 

 small vessel which were supposed to be dead have been 

 reproduced. The new polyps are seated on ringed stalks, 

 which rise up from within the original cells, and have each 

 only fourteen tentacles and their cells seven teeth ; a most de- 

 licate membrane unites the polyps to the mouths of their cells. 



In some of the young zoophytes in the larger vessel the 

 polyp stalk was ringed throughout, and in others the ring- 

 ing at the foot was preceded by a slight dilatation. The Clytea 

 vicophora* of Agassiz is figured with a polyp-stalk having a 

 like variety in its annulations, and his Clytea posterior with 

 cells rising up within each other. — T. Strethill Wright. 

 * ' Contributions to the Natural History of the United States,' vol. iv, pi. 29. 



