The condition encountered in some Rodents presents a more advanced stage. Thus the large intestine in the agouti (_Dasyprocta agouti_), shows the development of the spiral coil advanced as far as the second turn of the original loop (Figs. 389 and 390). It is readily seen that continued growth of this segment of the intestine leads to the formation of the complete colic spiral as found in the typical Ungulates. The same arrangement of the large intestine obtains in certain Lemurs among the Primates. Thus the proximal colon of the Slow Lemur (_Nycticebus tardigradus_) is seen in Figs. 421 and 422 to present a typical spiral coil, and similar conditions are encountered in other members of the suborder. =V. Caecal Apparatus and Colon in Hyrax.= We have left for our final consideration the aberrant and unique mammalian type found in _Hyrax_ (Fig. 378). In this remarkable little animal the large intestine develops a typical mammalian sacculated caecum at the ileo-colic junction, and in addition is provided further on with two symmetrical pointed lateral colic caeca of large size. It is quite true that this arrangement is unique among Mammalia, confined entirely to the members of the suborder formed by the single family of _Hyrax_, and that no strictly analogous disposition of the alimentary canal is encountered in the entire vertebrate series. Yet these aberrant structures are possibly capable of explanation, in regard to the method of their development, by reference to the caecal apparatus of certain phytophagous saurians, as _Iguana_ and _Cyclura_. In these forms (Fig. 326-330) the small intestine enters the colon somewhat asymmetrically, the opening being guarded by a well developed annular valve.