PLATE VII. 
Fig. 51. — Transverse section of ileum. L., longitudinal muscular bands; muc. C, < 
cular muscular coat ; Ep., epithelium. 
Fig. 52. — Transverse section through the furrow between two ileal folds. F., furrow; 
cu., cuticula; Ep., epithelium; conn., connective tissue; muc. C, circular 
muscles. L., longitudinal muscular band. 
Fig. 53. — Caloptcnus spretus. Epithelium of rectal glands. 
Fig. 54. — Surface view of the interior of the proventriculus ; d', central; d", molar 
processes of the teeth; a., longitudinal, interdental ridge. 
Fig. 55. — Longitudinal section of the wall of the proventriculus. 
Fig. 56. — Epidermal cells, seen from their outer surface. 
Fig. 57. — Spiral threads of the same trachea. 
Fig. 58. — Transverse section of the proventriculus; d', central: d", molar process of 
the teeth; ep., epithelium ; conn., connective tissue ; a., longitudinal ridge; 
C, subdental canal; muc, muscularis. 
