64 BRISTOL. 



DESCRIPTION OF PLATE IV. ^ 



Reproduced through the kindness of Professor Whitman froin the " Fest- 

 schrift zum siebenzigsten Geburtstage Rudolph Leuckart's," Leipzig, 1892, being 

 PI. XXXIX of that volume and appended to Professor Whitman's article, "The 

 Metamerism of Clepsine." 



Representing the first eight segments as reconstructed from sections and 

 surface views. X 50. The segments and nerves are numbered with Roman 

 characters, the annuli with Arabic numerals. The metameric and smaller 

 accessory sensillae of the dorsal side are represented in black, on the ventral side 

 by circles. 



REFERENCE LETTERS. 

 Alphabetically arranged. 



ant.n., anterior nerve. — h., buccal annulus. — d.b., dorsal branch of post, 

 nerve. — d.b. IV a. F, dorsal branch of nerves IV a. V. — f, rudimentary eyes. 

 — £^ principal pair of eyes. — f. i and 3, nephridial funnels. — g-d., bundles of 

 gland ducts. — i.l., inner lateral sensillae. — /nb.gl., labial glands. — l.s., longitu- 

 dinal septa. — ?«., median sensillae. — mg., marginal sensillae. — mg.s., marginal 

 sinus. — m.s., median sinus. — mid.n., middle nerve. — n.c., nerve cord. — neph. 

 1-2, 1st and 2d nephridia. — neph.p., nephridial pores. — o.l., outer lateral sen- 

 sillae. — p.b., post-buccal annuli. — ph.gl., pharyngeal glands. — post.n., posterior 

 nerve. — s. 1-4, septa. — s.n., septal nerve branch. — Ir.s., transverse sinus. — 

 V 1-2, funnel vesicles. — v.b., ventral branch of posterior nerve. 



