A Netu Species of Planocera. 147 



bring about a more normal and horizontal position in the body. 

 The penis consists of a delicate outer muscular tissue and an inner 

 alongside of the ductus ejaculatorius. The musculature is specially 

 well developed at the base of the penis where the inner joins the 

 outer. The arrangement of the muscle fibres is so complicated that 

 I was unable to determine it with certainty. Eadially arranged 

 muscular fibres pass from the inner to the outer musculature, the 

 remaining space between which is filled with connective tissue and 

 parenchyma cells. The free surface of the penis bears chitinous 

 spines and is surrounded by the very spacious antrum masculinum 

 produced by a folding in of the ventral wall of the body. The spines 

 (fig. 5) are small, closely set, and with their points slightly bent 

 forwards. In the neighbourhood of the free end of the ductus 

 ejaculatorius the spines are modified in such a way that they appear 

 in the form of small irregular processes which are twice as long as 

 the spine (fig. 4). 



The ductus ejaculatorius, which is lined with a cubical ciliated 

 epithelium, extends to the fixed end of the copulatory organ and 

 here divides into a dorsal branch leading to the granule-gland and a 

 ventral branch leading to the seminal vesicle. The granule-gland is 

 rather peculiarly shaped, as shown in fig. 3. It has a central canal 

 with smaller branching canals, which run approximately in the radii 

 of the granule-gland and open at various places in the central canal ; 

 this last leads into the ductus ejaculatorius, into which its distal end 

 opens. The radial canals are surrounded by numerous small 

 glandular cells, the small elongate nuclei of which are situated at 

 their bases. The number of glandular canals is considerable ; ten 

 to eleven are to be seen in median longitudinal section, and they 

 may altogether be present in considerably larger numbers. The 

 thin musculature of the granule-gland consists of longitudinal muscle 

 fibres provided with nuclei. The numerous nuclei of the parenchyma 

 lie on the outside of these. Extracapsular glands are not present. 

 Below and somewhat in front of the granule-gland lies a small oval 

 seminal vesicle provided with a low flat epithelium. Its musculature 

 is constituted of felt-like somewhat loose fibres. Both the vasa 

 differentia open separately into its blind end. Behind the pharynx 

 they turn round and pass into the large seminal ducts. They are 

 short, somewhat coiled canals with a collection of parenchyma nuclei 

 round their epithelium. Anteriorly they extend to the posterior end 

 of the pharynx and posteriorly to the neighbourhood of the female 

 genital opening without however joining here. 



We have to do with an animal not quite sexually mature, and 

 whose sexual apparatus is not yet quite functionally perfect. The 



