Items related to An account of the rats of Calcutta
Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 Excerpt: ...of 27 and 27"5 cm., were both males, but the next two largest, 25 6 and 25, were both females. Though practically every proportion of tail from 80 to 100 per cent. of total body-length was met with, 82 per cent. of the total fall within the limits 85 to 95 per. cent. The percentage length of the hind foot is a rather important measurement as it is an extremely valuable indication of the age of the specimen. The four rats which have as small a measurement as 16 per cent., are all very large and old rats with a body-length of 27 5,27, 257, 25 25 cm. On the other hand the two with a maximum of 21 per cent. are barely full grown, measuring only 19 and 19-5 cm. in body-length. With half-grown rats about 11 cm. in length, the foot is 28 to 30 per cent. of the body-length. Skull.--The most striking characteristic is the flatness of the antero-posterior curve and the general appearance of squareness shown by the cranium. The upper cranial surface, which in Mus rattus is pyriform, is here rather rectangular, the massive supraorbital ridges running back almost straight to join a very well-defined occipital ridge. The occipital bone is set obliquely instead of vertically, so that the condyles project most posteriorly of any part of the occiput. The anterior edge of the zygomatic plate sweeps boldly upwards and forwards to recurve to a deep emargination. This is not very well shown in the figures as the anterior curve should be much bolder. The nasals only just project beyond the gnathion or most prominent point of the premaxilla, so that they are much less prominent than in Mus rattus. The interparietal is generally three-sided with a well-marked anterior spike, but this may be suppressed so that the bone is an oval as is normally found in the young skull, vide f...
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