132 DESCRIPTION OF THE PLATES. 



Fig. 7. Imaginary transverse section of an Amphus. 

 a. Lateral lobes of the shell. 

 h. The gül. 



c. The most external fin lobe. 



d. Interior do. 



8. View of an Amphm cornigcrm, from below. 



a. Clj'peus. 

 hh. Lobi antennigeri. 

 cc. Lobi laterales. 

 d. Labrum. 

 pp. Mandibular. 

 ff. The indentations into which the lower ends of the lateral lobes are 



placed when the animal rolls itself up. 

 h. Rectum. 



9. Foot of an Apus cmicriformis, from the body region, \ery nuicli enlarged. 



10. Foot of the same species, from the central region of the tail, very much enlarged. 



11. The last foot of Apiis cancrifonnis, very much enlarged. 



12. Foot oi BranchijJiis stcif/naUs, very much enlarged. 



The designation of each of the feet is as follows : 



A. Basis, where it is aifixed to the body. 



B. Basis interna libera. 

 1 — 5 Fin lobes. 



K. Gill. 



L. Lobe protecting the gill. 

 /. Second protecting lobe. 

 . 13. A young Apus. 



a. Small feelers. 



b. Large feelers. 



c. Jaw. 



d. Rudiments of the feet. 



14. Young Branchipus : parts as in the last. 



15. Linniadia mauritiana, enlarged. 



B. Foot of Limnadia, parts as above. 



16. Branchipus, with a Trilobite shell, viewed from above. 



