108 EINAR LONNBERG, MAMMALS COLLECTED BY THE SWEDISH ZOOLOGICAL EXPEDITION ETC. 
These measurements indicate a very great individual variation in several re- 
spects. The most puzzling is perhaps the great difference in the relation between 
the parietal and frontal bones. In the Itiolu-specimen, for instance, the parietal is 
extremely short and the frontal extremely long, and in the Ntebbe-specimen the 
opposite condition prevails. But a comparisen shows that the Fort Hall-, the Kili- 
manjaro-, and the Northern Guaso Nyiri specimens with increasing resp. decreasing 
measurements gradually fill up the gap. A greater amount of material would no 
doubt prove this still better, but at the same time how very difficult it is to base 
new species and subspecies of Porcupines on cranial measurements. 
This variability is due to the comparatively long time during which each indi- 
vidual Porcupine continues to grow, and the great changes to which the skull is 
subjected during its growth. The factors at work are the development and exten- 
sion more and more backwards of the air sinuses, and the development of the mu- 
sculature which causes an increased growth and transformation of those parts of the 
skull with which it stands in connection. Through the influence of the musculature 
(m. temporalis) the parietal area is expanded and the lambdoid crest, so to say, 
moved backwards more in some specimens than in others. 
Both my specimens have the for H. galeata typical great height of the skull 
measuring from the palate between the first molars resp. 76 and 77 mm. The nasal 
processes of the premaxillaries are also as in the typical H. galeata very broad mea- 
suring at the middle of the nasopremaxillary suture resp. 18,5 and 20 mm. The 
maxillary portion of the zygomatic arch is inflated by the continuation of the air- 
sinuses into it, and its least width amounts therefore to about 15 mm. 
With the great dimensions of the skull of H. galeata a considerable bodily size 
is united. My specimen from Itiolu river measured when freshly killed 80 em. from 
snout to vent in a straight line. 
The Porcupines are rather common in certain parts of Brit. East Africa. In 
the surroundings of Nairobi its scratchings in the earth, and excrements were often 
observed. Now and then a dropped quill was found. At Escarpment station the 
Kikuyus complained about the damage the Porcupines did in the »shambas> chiefly 
on the potato-crop. But although I promised a high reward, the natives said they 
could not catch any. In consequence of their nocturnal life and their habit of remain- 
ing in their burrows over daytime Porcupines are very seldom seen. His Excellency 
Governor F. J. Jackson told me that during 16 years residence in East Africa he 
had not seen any living Porcupine. 
The specimen which was caught by this expedition (Pl. VI fig. 2) on the grass- 
steppe between Luazomela and Itiolu rivers had evidently intended to sleep over the 
day under an acacia-bush from which it ran out when some of the »boys» of the 
safari passed. It was then chased and clubbed. One day when stalking Buffaloes in 
a thornbush-patch south of Guaso Nyiri not far from the ford on the Marsabit-road 
I ran across the remains, mostly quills, of a Porcupine which evidently had been 
eaten by some carnivorous animal. My gunbearers declared with great certainty that 
it was the doing of a »Simba» = Lion. 
