20 Olive B. Davie.< : 



genital organs are quite simple, without aceessory oigans ; tli ■ 

 Huiy l-)e a flagelluin." 



The genus Cari/odes possesses the following thaiaiters. as given 

 bv Semper : — " Foot as usual, on the left of the edge of the manth- 

 there is a neck fold. There is a very peculiarly-sti uttured acces- 

 sory gland to the sheath (Scheide) (homologous to dart sac). Jaw 

 smooth. Teeth all unicuspid (as in Acavus). 



" For the characters of the shell, see Albers." 



External Features and General Description. 



As 1 was unable to procure any living spcciments of Caryodt^ 

 liufresnyi, I had to take the following description and nieasure- 

 ments from preserved animals. 



Shell : Height. 37 mms. ; greatest diameter, 12 mms. Mouth 

 Opening: Height, 10.5 nmis. ; width, 6 mms. Whorls, 5. Col c 

 brown or brownish green, with darker brown and yellow bands. 

 There is no umbilicus. 



The foot of an average specimen, preserved in spirit, measured 

 25 mm. in length. The animal itself was greyish brown, with a 

 lighter grey colour along the sole of tlie foot. 



Organs of the Mantle Cavity. 



The Mantle cavity is very long and narrow ; the kidney and heart 

 are situated at the posterior end of it; the bl(X)d vessels are large 

 and well marked. 



The Kidney is a somewhat triangular organ, with a depression 

 on one side, into which the heart is fitted, and its apex directed for- 

 wards. Arising from the apex is a bladder-like structure, which 

 runs backwards, down one side of the kidney and |)artly round its 

 base, to oi>cn al)out half way along this into the puhnonai ; 

 cliamljer. 



The Heart. The auricle is rather large compared with the ven- 

 tricle, it is extremely thin, being little more than a membranous 

 sac. The ventricle has thick walls and a small lumen. The heart 

 is surrounded by the pericardium, an extremely thin membrane, 

 in some places very ditlicult to make out in the sections. 



The Renopericardial canal can be seen very distinctly in section, 

 one of which is' represented in Fig. TIT. It is a short canal leading 

 from the pericardial cavity into the kidney; the canal is lined 

 along along its length by very definite, ciliated, columnar cells. 



