JOURNAL 



OF THE 



ROYAL mCROSCOPICAL SOCIETY. 



FEBEUARY 188.3. 



TEANSACTIONS OF THE SOCIETY. 



I. — Observations on the Anatomy of the Oribatidai. 



By A. D. Michael, F.L.S., F.R.M.S. 



{Bead lOtli Januarij, 1883.) 



Plates I. axd II. 



In preparing the work upon the British Oribatidse, "which I am 

 now writing for the Eay Society, it became desirable to deal, as 

 far as I was able, with the leading features of the anatomy. It was 



EXPLANATION OF PLATES I. and IL 

 Plate I. 



Fig. 1. — Alimentary canal of Nothrus theleproctus. X 50. a, cesophagus ; 

 6, ventricTilus ; d d, caeca ; e, small intestine ; /, colon ; g, rectum ; 

 i i, anal plates ; j j^ pre ventricular glands. 



„ 2. — Alimentary canal of Hoplophora magna, x 50. Same lettering. 



„ 3. — Alimentary canal of Bamceus genicidatus. x 35. Same lettering, 

 and c, ingluvies ; A. labium ; I, maxillae ; m, palpi. 



„ 4. — Part of the alimentary canal of Lclosoma pahnicinctum. Same letter- 

 ing, and n n, sujDposed duets from preventrieular glands. 



„ 5. — Ending of trachea in the acetabuliun of the third leg of Damceus 

 geniculatus. X 100. or, acetabulum, removed from the ventral 

 plate ; h, coxa ; c, femur ; d, trachea, ending in a small air-sac in 

 the acetabulum. 



„ 6. — Two tracheae oiBamceus geniculatus, uniting into a single trunk before 

 their attachment to the acetabulum of the second leg. 



„ 7. — Aii'-sac near mouth of Xothrus theleproctus. x 350. 



„ 8. — A portion of the left side ot Zeiosoma p^lmic^nctum, the dorsal shield 

 and all the internal oro;ans, except the super-coxal gland, having 

 been removed, a, wall of rostrum ; 6, first leg ; c, second leg ; 

 d, ventral plate ; e, super-coxal gland. 



„ 9. — The super-coxal gland of Leiosoma pilmicinctum. X 350. a, gland ; 

 6, globular body (vesicle ?). 



„ 10. — Mandible of Oribata globida (ordinary type in the familjO- x 180. 



„ 11. — Mandible of Pelops pjhrEonotus. x 600. Type of the genus Pelops. 



„ 12. — Mandible of Serrarius microcephahis. X 250. 



„ 13. — Serrated end of same mandible, x 500. 



„ 14. — Two teeth of same mandible, highly magnified. [Plate II. 



Ser. 2.— YoL. III. " E 



