10 Dr. M. Schultze on the Terrestrial Planarise. 



tity of small, circular, whitish points are scattered; these 

 cau just be perceived with the naked eye, are smaller and 

 closer together in the anterior half, and finally disappear en- 

 tirely at the head. The lower surface is uniformly greyish- 

 yellow, and exhibits close behind the middle the buccal orilice, 

 from which, in my specimen, the repeatedly folded, funnel- 

 shaped buccal extremity of the oesophagus projects, and 5 

 lines further back, the very small genital oritice. Eyes were 

 discovered by the microscopic examination of the margin of the 

 anterior half of the body ; they form blackish-brown pigment- 

 spots, usually of a crescent-shape, lying pretty close behind one 

 another in a single row, in the concavity of which, directed 

 outwards, there is a round transparent body, which does not 

 refract light very strongly, and in this respect exactly resembles 

 the similarly placed body, which must be regarded as a lens, of 

 the eye of our freshwater Planarice. 



The microscopic examination of the skin in the first place 

 confirmed the supposition expressed by F. Miiller, that in this, 

 as in the other Turbellaria, a ciliated epithelium exists, although, 

 from his observation recorded above, this hardly required mi- 

 croscopic proof. Although the ciliary coat in general had 

 suffered greatly by preservation in spirits, the epithelial cells 

 with their crown of cilia could, nevertheless, be unmistakeably 

 recognized in particular places. AVhether this coat of cilia be 

 general, or, as in many Mollusca, only present on particular 

 parts of the body, could not be decided. Nevertheless, from 

 analogy with the other Turbellaria, we are scarcely justified in 

 doubting that this coat is uniformly diffused. The ciliary cells 

 are colourless, and usually of a wedge-shape. In many of them 

 the thickening of the anterior cilium-bearing cell-membrane 

 was unmistakeable, and this appears to occur as universally in 

 these epithelial structures as in the cylindrical cells of the 

 intestine, according to the observations of Funke and KoUiker. 

 Below them there is a layer of irregulai'ly hexagonal pigment-cells, 

 which are the seat of the true principal colour. Bacillar bodies, 

 which, as is well known, occur so universally in marine and 

 freshwater Planarice, were entirely wanting in the skin of my 

 Geoplana. These, as I have repeatedly observed, may be very 

 well preserved in spirits, so that their absence could hardly be 

 due to the mode of preservation. 



As in the other Turbellaria, a cutaneous muscular network 

 follows beneath the cells of the skin, and in the first place, 

 indeed, a simple layer of closely approximated longitudinal 

 fibres. Below these is a closer layer of transversely placed 

 muscular elements. The former readily separate in connexion 

 with the cells of the epidermis, in the form of a thin membrane, 



