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Show 1881.] ANATOMY OF THE ERINACEIDSE. 407 peronei muscles are quite similar to those in Gymnura, but vary very much in the different species in their modes of origin and connections with the tendons of other muscles. Plantaris is well developed ; and its tendon passes into the sole of the foot precisely as in Gymnura ; but in some species the flexor digitorum brevis has also a calcaneal origin. The tibialis posticus is represented, as in Gymnura, by a pair of muscles in E. europceus, concolor, macracanthus, niger, and blanfordi; the internal muscle, however, is much smaller than in that genus, and arises from the head of the tibia only, and is altogether wanting in E. deserti, algirus, pictus^, heterodactylus, and diadematus, which have the centre callosity of the sole of the foot rudimentary or absent. Flexores digitorum et hallucis longi, although united into a single tendon before crossing the ankle-joint, are easily distinguishable in the leg. In the foot this tendon (in E. macracanthus, niger, blanfordi, pictus, micropus) is joined by a flexor accessorius arising from the os calcis. LumBrica/es exist in E. europceus, concolor, grayi, macracanthus, and micropus, but are represented bv one or two very small muscles connected with the deep flexor tendons for the third and fourth toes, or, as in E. micropus, for the second toe only. Flexor digitorum Brevis (noticed above), in the long-toed species, as E. europa?us, concolor, macracanthus, blanfordi, niger, arises almost wholly from the expanded tendon of the plantaris ; in the short-toed, as E. micropus. heterodactylus, diadematus, it is also largely connected with the fibrous aponeurosis, attaching the sides of the plantaris tendon to the os calcis, and a few fibres arise directly from the bone itself; but nearly all the muscular fibres arising from the os calcis external to the tendon of the deep flexor really belong to the abductor ossis metacarpi minimi digiti. Many other points of great interest are noticeable in the muscular anatomy of the species of the genus Erinaceus, which will be found treated of in the work from which these notes are taken (referred to in the footnote to the first page of this paper), which the writer hopes soon to publish. As might be expected from the comparatively much shorter jaws of the species of Erinaceus, the palate-ridges are less in number than in Gymnura, being nine only. The tongue is similar in general appearance; but the filiform papillae are bifid, and there are three circumvallate papillae; tonsils comparatively small, the depression shallow and vertical, opening outwards and backwards. The digestive organs in the Common Hedgehog have been described by Prof. Flower2. They probably more closely resemble those of G. raffiesii than do those of any of the other species of the genus. The chief differences observable are in the shape of the stomach (fig. 3, p. 398), which has the cardiac extremity more expanded ' Probably absent in E. micropus also ; but the specimens of that species examined had had the upper parts of the legs removed. 2 Lectures on the Comparative Anatomy of the Organs of Digestion of the Mammalia, by W . H. Flower, F.R.S., Hunterian Professor. Publ. in ' Medical Times and Gazette,' 1872, ii. p. 2. |