630 W. M. SMALLWOOD AND ELIZABETH G. CLARK 



The liver 



The liver occupies the posterior portion of the body cavity. 

 It is a large pyriform organ, the broad anterior end being slightly 

 bilobed in front. It is surrounded almost completely by the her- 

 maphroditic gland, whose ramifications may be seen lying on the 

 surface of the dark colored liver. In this species, the liver com- 

 pletely envelopes the stomach and the larger part of the kidney. 



RENAL SYSTEM 



It is impossible to determine anything very definite about the 

 extent of the nephridial organ without careful histological study. 

 However, it is possible to say that it consists of a main trunk with 

 numerous lateral anastomosing ramifications, which cover the 

 greater part of the dorsal surface of the stomach and probably 

 run into the liver. A short ureter (fig. 2, urt.) leads from the 

 kidney to the excretory orifice, a minute opening within the bran- 

 chial circle close to the anal papilla. With the main trunk, where 

 it merges into the ureter, is joined another duct (ren.-pi^cr.dt.), 

 which arises from the pericardium, where a valvular enlarge- 

 ment allows the passage of fluid from the pericardium to the renal 

 trunk. 



RESPIRATORY AND CIRCULATORY SYSTEMS 



These two closely related systems embrace the branchiae, the 

 heart, the blood vessels and blood spaces, together with the blood 

 gland. The heart lies within the pericardium on the upper sur- 

 face of the posterior portion of the liver mass just anterior to 

 the branchiae. It consists of an anterior muscular ventricle 

 (fig. 4, V.) and a posterior thin-walled auricle (aurl.). From the 

 apex of the ventricle a large blood vessel runs forward, giving off 

 lateral branches to the liver and other organs. Just anterior to 

 the liver mass occurs an enlargement, which sends one vessel 

 (va.sng.gen.) to the genitalia, one to the blood gland {gl.sng.) and 

 another (va.sng.buc.) which continues anteriorly to surround the 

 buccal mass. Throughout the integument are numerous blood 

 spaces, which lead to the posterior end of the body and pour 



