Troglodytice comes next, by the ancients called Midoë, and by some Michoë; here is Mount Pentedactylos, some islands called Stenæ Deiræ,[679] the Halonnesi,[680] a group of islands not less in number, Cardamine, and Topazos,[681] which last has given its name to the precious stone so called. The gulf is full of islands; those known as Mareu are supplied with fresh water, those called Erenos, are without it; these were ruled by governors[682] appointed by the kings. In the interior are the Candei, also called Ophiophagi, a people in the habit of eating serpents; there is no region in existence more productive of them. Juba, who appears to have investigated all these matters with the greatest diligence, has omitted, in his description of these regions—unless, indeed, it be an error in the copying—another place called Berenice and surnamed Panchrysos,[683] as also a third surnamed Epidires,[684] and remarkable for the peculiarity of its site; for it lies on a long projecting neck of land, at the spot where the Straits at the mouth of the Red Sea separate the coast of Africa from Arabia by a distance of seven miles only: here too is the island of Cytis,[685] which also produces the topaz. Beyond this are forests, in which is Ptolemais,[686] built by Philadelphus for the chase of the elephant, and thence called Epitheras,[687] situate near Lake Monoleus. This is the same region that has been already mentioned by us in the Second Book,[688] and in which, during forty-five days before the summer solstice and for as many after, there is no shadow at the sixth hour, and during the other hours of the day it falls to the south; while at other times it falls to the north; whereas at the Berenice of which we first[689] made mention, on the day of the summer solstice the shadow totally disappears at the sixth hour, but no other unusual phænomenon is observed. That place is situate at a distance of six hundred and two miles from Ptolemais, which has thus become the subject of a remarkable theory, and has promoted the exercise of a spirit of the most profound investigation; for it was at this spot that the extent of the earth was first ascertained, it being the fact that Erastosthenes, beginning at this place by the accurate calculation of the length of the shadow, was enabled to determine with exactness the dimensions of the earth.