Boyal Microscopical Society. 209 



lobe, the tube at the same time reaching fully up to the neck. 

 Similar instances occur with F. eornuta; and that this inordinate 

 extension with Melicerta is also confined to the footstalk we receive 

 confirmation in the fact, that during acts of evacuation when the 

 cloacal orifice is brought to the verge of the lengthened tube, the 

 body of the animal retains its normal proportions ; this abnormal 

 attenuation being consequently confined to the footstalk. 



Much discrimination is exercised by these clever artificers in 

 the several processes they adopt in the acts of hrich-mahing and 

 hrich-laying ; the heterogeneous mass that is first brought about 

 . the disk by the force of the ciliary currents is seen to pass beneath 

 a pair of small ciliated processes, which exercise a rapid discrimi- 

 nation in the selection of those specially adapted for alimentary 

 purposes and others for the formation of these pelletoid bricks, 

 which particles, when so selected, are seen to emerge from beneath 

 the two ciliated processes which conduct this operation, and to 

 course along the chases beneath the lateral margins of the dorsal 

 lobe downwards into the pellet chuch or moiild, where this granular 

 matter becomes blended with a cement, secreted during the process 

 of manufacture, and are moulded by the action of the contained 

 cilia, by which they are also shaped and finished off in the peculiar 

 form, resembhng somewhat that of the pellets of the Minie rifle, 

 with this difference, that the sides forming their bedding surfaces 

 are not parallel, but radiate with their axes from their shoulders to 

 the centre of the tube. 



The pellets are not formed of one homogeneous consistency, but 

 preserve a central core through the granulate matter of which they 

 are composed, this core is perfectly transparent on an end view as 

 represented by Plate LXXXIII., Fig. 14, and a side view which, 

 by careful adjustment of focus, presents a horizontal section such 

 as shown by Fig. 15. The hedding surface maintains a tolerably 

 constant form and proportion, while the more abruptly tapering 

 outer ends are seen at times to deviate considerably from their usual 

 shape, and frequently to assume an extraordinary degree of attenua- 

 tion. 



These pelletoid hrielcs are laid in a pecuhar manner, they are 

 bonded in their horizontal heds, and hreah joint the one with its 

 neighbour, so that while there are thirty-two pellets in the whole 

 circumference, there are sixteen only in each horizontal course, 

 presenting in elevation perfectly straight and unbroken lines, in- 

 ducing by such a disposition a series of helices around the periphery 

 of the tube when the tube is viewed vertically, but any departure 

 from that position modifies the character of the curve more or less, 

 according to the degree of inclination, as in the instance before us. 



This particular disposition of the pellets in the construction of 

 the tube ensures great strength, and is eminently calculated to 



