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EXPLANATION OF PLATES. 
Plate V. Sections through the proventriculus of Gryllus pennsyl- 
vanicus. All greatly enlarged. 
Fig. 1. Longitudinal section through the median denticles. 
Fig. 2. Transverse section passing through two folds of the 
anterior division of the proventriculus. 
Fig. 3. Surface view of a portion of one of the dental folds 
showing the chitinous partition and four of the transverse 
rows of teeth. 
Fig. 4. Transverse section of proventriculus passing through the 
median denticles. 
Fig. 5. Transverse section of fold cut in the region of the lateral 
denticles. 
Fig. 6. Lateral view of two adjacent inner barbated lobes. 
br. =Bristles of anterior division of proventriculus. 
ch. p.=Chitinous partition between dental folds. 
c. m.=Circular compressing muscles. 
ce. v.=Cardiac valve. 
ep. = Epithelium. 
i. b. 1. =Inner barbated lobes. 
in. = Intima. 
1. d.=Lateral denticle. 
1. t.= Lateral tooth. 
m. d.= Median denticles. 
