reynell : on cassidaria rugosa. 297 



Reprobuctive System. 



Penis (Fig. 8, P.). Very large and directed backwards when 

 retracted, more or less oval in section, the free end curving downwards 

 following the curve of the floor of the pallial cavity, blunt at the 

 apex. At the right-hand side near the apex is a small pointed 

 papilla (Fig. 8, P.P.). 



Testis. Is a large whitish, somewhat granular -looking organ, 

 which divides with the liver, as before mentioned, the visceral sac, 

 and reaches quite to the apex. 



The duct leading to the vas deferens is very short (Fig. 1, S.iy.) 

 where it has been cut through and the visceral sac turned back, 

 joining the vas deferens at S.D"., Figs. 1 and 8. 



Seminal Duct. Directly after entei'ing, the duct enlarges very 

 suddenly, forming a pear-shaped receptaculum (Fig. 8, P.), which 

 contained a certain amount of a reddish-brown granular substance. 

 The upper part of the walls of this receptaculum are rather thin, and 

 it is attached on the vmderside to the floor of the pallial chamber. 



On leaving the receptaculum the seminal duct or vas deferens 

 (Fig. 8, S.D.) runs through a thick- walled tube which is formed by 

 a thickening of the floor of the pallial chamber, semicircular in section ; 

 this becomes free as the base of the penis proper is reached. 



The large penis is nearly solid (shown in section, Fig. 8), and in 

 section the seminal duct shows as a vertical slit at the right-hand side 

 (Fig. 8, S.D'".), and follows the contour of the organ right round the 

 blunt extremity till it reaches the outlet at the papilla. 



ClKCULATORY, NeRVOTJS, AND MuSCULAR SySTEM. 



"Want of material has prevented my paying particular attention to 

 these important paints of the anatomy of the animal. 



The heart is of the usual monotocard type, and is provided with 

 a very thin-walled auricle (Fig. 7, Au.) and a thick-walled and 

 muscular ventricle enclosed in the pericardium. It is situated at the 

 base of the kidney. The large thin-walled efferent vessel (Fig. 7, 

 S:/. V.) carrying the aerated blood to the heart makes a U-shaped turn 

 before entering the pericardium. The aortic trunk (Fig. 7, Ao.) 

 swells on leaving the ventricle and then decreases in size. The aorta 

 soon divides, the branches leading in opposite directions, one supplying 

 the anterior and ventral parts of the body and the other the organs 

 contained in the visceral sac. 



Nervous System. I can say but little with regard to this. The 

 nerve-collar, situated round the oesophagus close behind the buccal 

 mass, is enveloped in a dense sheath of connective tissue, and the 

 ganglia are not particularly distinct. The two cerebral ganglia 

 above the oesophagus and the two pedal ganglia below it are to 

 some extent distinct on account of their yellowish tint. The pleural 

 ganglia are not so distinct and appear to be placed rather low, so that 

 the cerebro-pleural connectives are longer than the pleuro-pedal. The 

 right pleuro-visceral connective is a very distinct flat band, 2 mm. 

 wide, which runs a little to the left-hand side of the crop after 

 crossing over from the right pleural ganglion. 



