The species described by Dr. Hansen as _H. talpoides_ is probably distinct from that of Walker, though both come from equatorial West Africa. Dr. Hansen's species, which may be called _H. hanseni_, has been found living on the body of a large rat, _Cricetomys gambianus_; the Insect occurred on a few specimens only of the mammal, but when found was present in considerable numbers; it runs with rapidity among the hairs and apparently also springs. The nature of its food is by no means clear. Not the least remarkable fact in connexion with this peculiar Insect is its gestation. The young are borne inside the mother, {219}apparently about six at a time, the larger one being of course the nearest to the orifice. Dr. Hansen thinks the young specimens are connected with the walls of the maternal passages by means of a process from the neck of each. But the details of this and other points are insufficiently ascertained; it is, indeed, difficult to understand how, with a process of the kind of which a fragment is shown in Fig. 116, _b_, the Insect could fix itself after a detachment for change of position. The young is said to be very like the adult, but with a simpler structure of the antennae and abdomen. On the whole, it appears probable that _Hemimerus_ is, as stated by Dr. Hansen, a special family of Orthoptera allied to Forficulidae; further information both as to structure and development are, however, required, as the material at the disposition of the Swedish entomologist was very small. {220}CHAPTER IX ORTHOPTERA CONTINUED—BLATTIDAE, COCKROACHES FAM. III. BLATTIDAE—COCKROACHES. _Orthoptera with the head deflexed, in repose concealed from above, being flexed on to the under-surface with the anterior part directed backwards. All the coxae large, free, entirely covering the sternal surfaces of the three thoracic segments, as well as the base of the abdomen. The sternal sclerites of the thoracic segments little developed, being weak and consisting of pieces that do not form a continuous exo-skeleton; tegmina and wings extremely variable, sometimes entirely absent. The wings possess a definite anal region capable of fan-like folding; rarely the wing is also transversely folded. The three pairs of legs differ but little from one another._ [Illustration: FIG. 118.—_Heterogamia aegyptiaca_. A, male; B, female. (After Brunner.)]