494 THOS. H. MONTGOMERY, 



shaped, owing to the central portion in such cases being lighter than 

 the peripheral, The high papillae of the groups mentioned above also 

 show a clear, central core. 



Cuticle (transverse Sectio n). Five different kinds of pro- 

 rainences raay be noted: 1) a pair of papillae occurring at the centre 

 of each group of high papillae {a Figs. 2, 3, a Figs. 1, 3). These are 

 the most elevated and broadest of all ; they are rounded at the summit 

 (which is of a lighter color than the basal portion), and appear more 

 or less barrel-shaped in outline. The peripheral portion is darker and 

 denser than the axial. Attached close together in a ring around the 

 basis of the summit are found numerous, white, thick hairs, of greater 

 diameter than the papilla itself. They are not stiff but very pliable, 

 as is shown by the fact that they are generally irregularly bent and 

 interlaced together (these hairs are shown in Fig. 4, but in Fig. 3 

 are purposely not reproduced in order to show more clearly the form 

 of the central papillae). 2) High papillae situated around the pair 

 just described, about 12 — 20 in number in each group, the number 

 being variable (b Figs. 1, 3). The highest of these (those situated 

 nearest the large central pair) have about the height of the central 

 pair, while those towards the periphery of the group are only one- 

 half or one-third so high. All of these are much narrower than those 

 of the large central pair, the more central ones being finger-shaped, 

 the more peripheral ones more conical. Their summits are either 

 rounded or somewhat pointed, and each bears on its summit a few 

 Short, delicate hairs ; their bases are the broadest portions. Like the 

 preceding kind, these papillae have a darker periphery and a lighter 

 core, but they are not so dark in color as the preceding. Both these 

 kinds are translucent. 3) The lowest and most numerous papillae, 

 which occupy all the space between the groups of the high papillae, 

 are placed close together (c Figs. 1, 3, 4). Their substance is denser 

 and darker than that of any other cuticular prominence : they appear 

 lighter on surface view owing to their smaller degree of elevation. 

 They are usually longer than high, lowest at the margins; but they 

 Vary somewhat in form, and a few are higher than broad. Their 

 summits have a dentatcd appearance, i. e. each summit is multi- 

 tubercular; these apical tubercles vary in size and have a more or 

 less roundod-conical shape. Each papilla is transversed by a varying 

 number of narrow canals, which are directed perpendicularly ; the ex- 

 ternal opening of each of these lies between two of the tubercular 

 prominences. These canals do not extend into the underlying übrous 



