362 



1990. The left ulna, in longitudinal section. 



1991. The left radius, in longitudinal section. 1992. The ossa innominata. 

 1993. The right femur. 1994. The left femur, in longitudinal section. 

 1995. The right tibia. 1996. The left tibia, in longitudinal section. 

 1997. Two fibulae. 1998. The right calcaneum. 

 1999. The right astragalus. 2000. The right patella. 



Genus Cavia. 



Dental formula : i |=i, p =}, m ^=20. 



2001. The skeleton of the Guinea Pig (Cavia aperea, domesticated variety; Cavia 

 cobaia, Schreber; Mus porcellm, Linn.). 



The vertebral formula is : 7 cervical, 1 3 dorsal, 6 lumbar, 4 sacral, 5 caudal. Tbe trans- 

 verse processes of the last cervical are perforated. Eight pairs of ribs articulate directly with 

 the sternum, which consists of five bones. The ridge representing the combined anapophyses 

 and metapophyses rises distinct from the diapophysis of the ninth dorsal, bifurcates at the 

 eleventh, the two processes becoming distinct on the thirteenth, and so continuing to the 

 penultimate lumbar, the anapophysis disappearing on the last lumbar vertebra. The supra- 

 spinal fossa is narrower than the infraspinal one : the long acromion expands into an inequi- 

 lateral triangular plate, the anterior notch not being deep enough to produce the bifurcate 

 structure. The humerus is perforate between the condyles, but not at the inner condyle. 

 The pollex is absent from the fore foot, and both first and fifth toes are wanting on the hind 

 foot. The distal third of the fibula is closely applied to the corresponding part of the tibia. 

 A fubella is preserved above each condyle of the right femur ; one of them has been lost on 

 the left leg. 



Purchased. 



2002. The skeleton of a Guinea Pig (Cavia aperea}. 



In both specimens the rudiment of a third trochanter projects from the middle of the outer 

 side of the shaft of the femur. 



Mus. South. 



