PRENTISS : THE OTOCYST OF DECAPOD CRUSTACEA. 



251 



EXPLANATION OF THE PLATES. 



All Figures were outlined with an Abbe camera lucida. Tube length was 

 usually 160 mm., witli projection distance to tlie table, 410 mm. The magnifi- 

 cations are given with the descriptions of the several figures. Drawings were 

 made from sections, unless the contrary is stated. Tlie orientation of the figures 

 is given for each plate. 



ABBREVIATIONS. 



cLgl. . 

 cl. gn. . 

 cl. mil. 

 co'nt. cic'oes 



crs. sns 

 eta. 

 eta', 

 dt. . 

 fbr'. 

 fbr. ass 

 fbr. e. 

 fbr. n. 

 fbr. pi'ph 



fg- ■ 



gib. . 

 gn. olf. 

 h'drm. 

 lab. a. 



lab. p. 

 lu. . 

 mal. . 

 mb. xph 

 n. at.l 

 n. nt.2 

 n'bl. . 

 n'tem 



Gland cell. 

 Ganglion cell. 

 Matrix cell. 



Circumoesophageal con- 

 nective. 

 Sensory crista. 

 Cuticula. 

 New cuticula. 

 Duct. 



Fibrillations. 

 Association nerve fibre. 



Central nerve fibre. 

 Nerve fibre. 



Peripheral nerve fibre. 



Flagellum. 



Globulus. 



Olfactory ganglion. 



Hypodermis. 



Anterior lip of orifice 

 to otocyst. 



Posterior lip of same. 



Lumen of otocyst. 



Hammer. 



Spherical membrane. 



Antennular nerve. 



Nerve of 2d antenna. 



Neuroblasts. 



Neurilemma. 



?)/. tit. . . . Sheath nucleus. 



71. opt. . . . Optic nerve. 



71. ot. . . . Otic nerve. 



?i'/«7. at.l . . Neuropil of antennule. 



7i'pil. at.2 . . Neuropil of antenna. 



7i'pil. opt. . . Optic neuropil. 



71. teg. . . . Tegumentary nerve. 



of. ... ■ Orifice. 



oCcij. . . ■ Otocyst. 



ot'lth. . . . Otoliths. 



pinn. . . . Pinnules of hairs. 



pr'c. prpl. . Protoplasmic process. 



rm. I. . . . Lateral branch of an- 

 tennular nerve. 



1-0 Rostrum. 



set.' .... Group hairs. 



set.fil. . . . Thread hairs. 



set. I. . . . Lateral hairs. 



set. 711. . . . Median hairs. 



set. olf . . . Olfactory hairs. 



set. ot. . . . Otic hairs. 



set. p. . . . Posterior hairs. 



set. ta. . . ■ Hook hairs. 



set. tac. . . Tactile hairs. 



tb. set. . . ■ Hair tube. 



tct. .... Tectum of otocyst. 



tu. myl . . Myelin sheath. 



