1888.] THE CARPUS AND TARSUS OF THE ANURA. 181 



VI. EXPLAISTATION OP THE PLATES. 



In order to facilitate comparison, all the figures are drawn in the same re- 

 lative position. Each represents the dorsal surface of the left member. 



Unless otherwise stated, all the preparations are represented as transparent 

 ohjects. In drawing them, we have stippled ossified parts and left the cartil- 

 lages clear ; the effect thus obtained is more natural than that expressed in the 

 more orthodox custom of stippling the latter. 



Ligaments are indicated in black. 



Plate VII. 



Fig. 1 . Pipa americana, adult (^ . Left fore foot, from above. Drawn as an 

 opaque object. X 2^. 



2. Pipa americana, very young specimen. Left fore foot. Ossification 



has not yet begun. X 30. 



3. Xenopus (cevis, adult 2 • Lpft hind foot. X 4. 



4. Xenopus Icevis, adult j . Left fore foot. Elements slightly disarticu- 



lated. X 5. 



5. I)iscofflosst(s picius, yo\ir\g S])eciiaen. Left fore foot. X 10. 



6. Biscoglossus jiictus, adult (j", 42 mm. in length. Left fore foot. All 



the elements are completely ossified. The white areas represent 

 compact bone, the dark ones spongy bone. X 4. 



7. Bombinator igmeus, adult J , 37 mm. in length. Left fore foot. X 7. 



8. Bombinator iyneus, adult J, 26 mm. in length. Left hind foot. 



X 7. 



9. Aliftes obstetricans, tadpole, 24 mm. in length from mouth to vent. Left 



fore foot. X 20. 



10. Alytcs obstetricans, adult $, 40 mm. in length. Left hind foot. The 



astragalus and calcaneus and the metatarsals have alone begun to 

 ossify. X 4. 



Plate VIII. 



11. Pelodytes punctatus, length 30 mm. Left fore foot. The hand is 



rotated upon the radius and ulna through more than a right angle ; 

 to facilitate comparison with the other figures, the fused radius and 

 ulna are represented as completely disarticulated and flattened out. 

 X7. 



12. Pelodytes punctatus, length 30 mm. Left hind foot. X 8. 



13. Pelodytes pimctatus, outline sketch of preaxial portion of the tarsus of 



the above preparation, to show tbe course of the ligament connecting 

 the tarsaha of the halhix and pre-hallux. X 16. 



14. Xenophrys monticola, young specimen, 27 mm. in length. Left fore 



foot. X 5. 



15. Xenophrys monticola, enlarged drawing of tbe postaxial distal portion 



of fig. 14. The element k has been slightly displaced, in order to show 

 more fuUy the vestigial 5th carpal. X 16. 



16. Xenophrys monticola, adult of 40 mm. length. To show ossification of 



the vestigial 5tb carpal. X IS. 



17. Xenophrys monticola, length 27 mm. Left hind foot. X 12. 



18. Pelobates fuscus, adult ^ , 54 mm. in length. Left fore foot. The 



fused radius and ulna have been disarticulated from the hand and 

 laid flat ; during life the radius articulates in tbe concavity seen at 

 the proximal end of the lunatum {I.). X 7. 



19. Hyla cmndca, adult ^ , 75 mm. in length. Left hind foot. X 3^. 

 19a. Phyllomcdusa dacnicolor. Calcar, showing absence of the proximally 



directed process of its second segment, x 4. 



20. Hyla cmndea, adult $ , 75 mm. in length. Left fore foot. X 4|. 



21. Hyla arborea, late tadpole. Left hind foot. Ossification has not yet 



begun. X 14. 



22. Pse%ulo]}hrync bibronii, cf, 22 mm. in length. Left fore foot. X 12. 



