354 DAVIDSON BLACK 
indicative of a close relationship between the two groups. ‘This 
would appear to be but another example of resemblance due to 
convergent or analogous evolution (vide Gregory, 19, p. 400). 
Distinctive characters of convolutional pattern in Giraffidae 
The chief peculiarities of the convolutional pattern in the 
Giraffidae, as evidenced by the material at my disposal, may be 
enumerated as follows: (a) a well marked and caudally situated 
ramus descendens suprasylvii; (b) a dorsally placed suprasylvian 
sulcus separated from the pseudosylvian acuminis by a broad 
area in which is developed a very evident arcuate constellation; 
(c) a small presylvian area (rostral to presylvian sulcus). 
TABLE 1 
ee constELLaTION | (3) PRESYLVIAN AnEA 
(miami cosagoebooes Well marked and Present Small—no sulcus 
caudally placed intraorbitalis 
@ervidaenwe see ce Absent 
Antilocapridae......... Absent 
Bovidaeren «see Absent 
Bovidae* (exceptions) | Variable and Usually larger 
when present, than in Giraffi- 
not so caudally dae 
placed 
Trac alice meres Absent 
Camelidae.............] Usually separat- Large—sulcus in- 
ed from sup- traorbitalis well 
rasylvian and developed 
not so caud- 
ally placed 
Hippopotamidae....... Absent 
Suidaeat< .0ee scree Absent 
quidacte sme seers Not caudally Large—sulcus in- 
placed traorbitalis well 
developed 
RAapInid sen. eae eeeer Frequently sep- Similar to Equi- 
arate from dae 
suprasylvian 
Rhinocerotidae........ Similar to Equi- Similar to Equi- 
dae dae 
* Vide supra, page 348. 
