More than this, he seems to be the earliest ornithologist, perhaps the earliest zoologist, to conceive the idea of each genus possessing what is now called a " type " - though such_a term does not occur in his work; and, in like manner, without declaring it in so many words, he indicated unmistakably the existence of subgenera - all this being effected by the skilful use of names.
In 1855 Gray brought out, as one of the Museum publications, A Catalogue of the Genera and Subgenera of Birds, a handy little volume, naturally founded on the larger works.
SPINY SQUIRREL, a book-name for a group of African ground squirrels, characterized by the spiny nature of the fur of the more typical forms. They form the genus Xerus, which is split up into a number of subgenera; Xerus rutilus of Abyssinia and East Africa belonging to the typical group, while the striped North African X.
All the European hamsters show more or less black on the under-parts, but the small species from Central Asia, which constitute distinct subgenera, are uniformly grey.
Hares (and rabbits) have a cosmopolitan distribution with the exception of Madagascar and Australasia; and are now divided into numerous genera and subgenera, mentioned in the article FIG.