96 SELECTED NOTES FROM 



ready to make their exit. Previous to leaving, they cast their 

 first skin, which may frequently be seen left behind. 



More on Tick's mouths, when materials have been obtained 

 sufficient to render a discussion of use — mine was merely a 

 suggestion thrown out to excite remarks from other members. I 

 do not now, after examination of the mouth in several other 

 Ticks, in Human Lice, and in some Pycnogons, think it quite 

 correct, yet neither does Dr. Moore's theory of a " closely fitting 

 piston," appear to accord better with what I find. T. West. 



EXPLANATION OF PLATE IX. 



Fig. 1. — Proboscis of Tortoise-Tick, x 100. — m, m, Mandibles ; 



I, toothed Labunii or Rostrum. 

 Fig. 3. — Ideal transverse sections of the Labium, taken at the points 



a and b, shown on Fig. 2. 



Selcctcb 1Rotc0 from tbc Socict^'a IRote^ 



INORGANIC. 



Clifton Oolite. — The small egg-shaped nodules found in this 

 rock seem to be formed by successive layers deposited round 

 minute fragments of various foreign bodies which serve as nuclei. 

 Among these may be noticed portions of Echinus spines, — bits 

 of Coral, such as Favosites^ Hdio/ites, and others, — fragments of 

 Encrinoids, — minute shells and Foraminifera, etc. They all seem 

 to be of animal, not of vegetable origin. The same organisms 

 which are found in the Oolite are found also in the Carboniferous 

 Limestone ; and at CHfton may be seen strata of Oolite, some 

 2o feet thick, with layers of the Limestone lying both above and 

 below them. Here and there one finds, imbedded in the mass of 

 Oolite, pieces of Encrinoids of considerable size, — as large 

 sometimes as a small bullet. The nodules possess a granular, 

 rather than a crystalline structure, and often exhibit concentric 

 rings. 



The formation of this rock one may imagine to have proceeded 

 somewhat as follows:— On a shallow, sandy shore, partly strewn 

 with broken bits of shells, corals, encrinoids, etc., there has been 



