328 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



LETTEIIINC; OF THE PLATES. 



Ab I, Ah II, Ab III, first, second, and tliinl i>:iirs ol' altdominal appeiidafjes of the i-niliryo. PI. XVII. 



««., aims (=proetodoeiim). PI. xvii. 



ant. at., anterior branch of the stalk of the mushroom body. 



Ut app.gang., ganglion of the first pair of appendages. 



npp.' n., nerve of Ist pair of appendages (" cheliceral nerve ")• 



asc. at. M. b., ascending branch of the stalk of the mushroom body. 



b. c. /., bulb of the cerebral lobe {" tubercle protocerebrah" of Viallanes. 

 br,, brain. 



c. (J. c, c, g. & ., c. g. c" ., groups of cerebral-ganglion cells. 



c/i. c, chromatic cells, small ganglion cells, or aprotoplasmic cells of the mushroom body. 

 c. I., cer. I., cer. lobe, and cer. gang., cerebral lobe or g.anglion. 



e. ch., "Chiasma," or bundle of twisted nerve-fibers connecting the outer or third with the second division of 

 the lateral-eye lobes (" Chiaama externu" of Viallanes). 

 c. com., c. I. com., and com. c. I., cerebral commissure. 

 /., .sense organ of embryo. PI. xvii. 



f'.f"., bundles of fibers arising from largeganglion cells. PI. vi. 

 fnsc, fascia or buudle of fibers arising from the ganglion cells. 

 g. Ut app., ganglion of the first pair of appendages, 

 i. (/. I., inner ganglionic layer of lateral eye lobes. 

 /., labrum of embryo. PI. XVII. 



lat. h., " lateral heap," or "dorsal organ " of the embryo. PI. xvii. 

 lat. eye /., lateral-eye lobe. 



lat. eye V., proximal or first division of the lateral-eye lobes. 

 lat. eye V., second or middle division of the lateral-eye lobes. 

 lat. eye P., third or external division of the lateral-eye lobes. 

 lat. eye n., lateral-eye nerves. 

 lat. eye n. r., origin or root of lateral-eye nerve. 

 1. g. c, large ganglion cells. 



I. .ft., lateral branch of stalk of mushroom body. 

 (. /. «., I. teg. n., lower tegumental nerve of the brain, 

 m., mouth of the embryo (.stomodicuiii). 

 m. b., niudhroom l>ody or pedunculated body. 

 m. eye 1., median-eye lobe. 

 m. eye n., median-eye nerve. 



m. eye n. e., external lobule of the median eye-lobes, 

 m. eyen. r., root of median-eye nerve. 



m. «., unpaired fronto-median nerve situated between the lower tegumental nerves. 

 cc., cesophagus. 



»i'. to n^. neuromeres, or ganglia of the embryo. 

 O'. com., oesophageal commissure or connective. 

 poat. a:, com., pi)st(esophageal commissure. Plate xvi. 

 pr. w. com., preo'sophageal commissure. Plate xvi. 

 at., stomach. Pis. .win and xix. 

 at. mb., stalk of the mushroom body. 



.8. m. g. c, a. m. g. <•'., small ganglion cells forming tlii^ ruffle-like masses of the mushroom body. 

 teg. n., tegumental nerves of the (esophageal ring, 

 w. teg. n., upper tegumentary nerve. 



I, II, III, IV, V, VI, the six pairs of ceph.ilothoracic appendages. 

 / g., VI g., ganglia of the first and sixth pair of appendages. 



