416 PBECT SLADEN TRUST EXPEDITION. 



a strand or are free iu its cavity. It would seem, therefore, tliat some of the liver cells 

 are excretory in function, and are dropped, into the follicle as they hecome extended 

 with excreted material. 



The heart lies somewhat to the right of the median line. The walls are thin, and 

 not strong. From the ventricle issue the anterior and posterior aortas, but the aortic 

 system is not much developed, as is perhaps natural in an animal that has no gills. The 

 arteries are thin, and do not extend beyond the level of the genital orifice in front and 

 of tlie anus behind. The musculature of the ventricle also is feebly developed. The 

 venous system is extensive and the veins are pi-ovided with valves not only near the 

 heart but in parts far from it, e. g, throughout the length of the lateral veins and 

 venules and between the blood lacunsB of the foot. The auricle has a large extension on 

 the left, enclosed by a corresponding extension of the pericardium ; it adheres to the 

 anterior part of the ventricle, the line of adhesion being zigzagged, and on the right it 

 is attached to the wall of the pericardium. 



The kidney is a shallow chamber lying on the surface of the hermaphrodite gland, 

 and sending downward prolongations between its follicles. In front it bifurcates like 

 the hermaphrodite gland, and is divided behind into a number of irregular tubes by the 

 dorso-ventral muscles and the projecting genital lobes. The renal opening is minute 

 and near the anus. From the reno-pericardial opening a tube passes dorsally through 

 the substance of the kidney and dilates in the median line into a flattened vesicle. 

 Posteriorly this sub-divides into three fine ducts, each opening into the kidney by a 

 minute aperture. The wall of the kidney is formed by a layer of large, clear, cubical 

 cells, the nucleated protoplasmic portion of which is limited to a small quantity at the 

 base of the cell. 



The genitalia are large, and occupy most of the right-hand side. The hermaphrodite 

 gland consists of a single undivided mass of roughly triangular shape, bifurcating in 

 front so as to enclose the am])ulla and the spermatotheca in the fork. It is traversed 

 by branches of the liver, which enter it from below^ by the dorso-ventral muscle bands, 

 and by various prolongations of the blood lacunar of the foot. The kidney also sends 

 prolongations into its upper surface. It presents a series of lobes the outer layers 

 of which are formed by masses of ova. Witliin each lobe is an ample loculus, larger 

 than the whole mass of ova, containing spermatozoa in all stages of development. But 

 there is no symmetrical arrangement of ovarian follicles round a central male follicle. 



The hermaphrodite duct is thin and short, but swells out into an unusually large 

 pear-shaped ampulla which again contracts into a thin tube. After a short straight 

 course this tube bifurcates. The male portion runs forward and describes a complete 

 loop, after which it first dilates into a prostatic portion (but without any trace of a 

 separate prostate gland) and then contracts into a muscular portion, terminating in a 

 thin conical glans penis. No trace of spicules or other armature was found in this or 

 any part of the genitalia. After tJie main bifurcation dividing the male and female 

 branches, the female branch runs backwards for a little distance as a short tube and 

 then itself bifurcates. A short duct leads to the sjjermatotheca, which is large, globular, 

 and single, no trace of a second receptaculum seminis being found. The walls of the 



