178 Thirty -fifth Be port on the State Museum. 



tory apparatus. The lining of the mouth consists of ciliated epi- 

 thelium cells, continuous with the labial palpi, or, as they are desig- 

 nated by some authors, the oral tentacles. The mouth connects with 

 the stomach by a very short oesophagus, the lining of which also con- 

 sists of ciliated epithelium, the food being conveyed to the stomach by 

 the action of the cilia. 



The stomach (PI. 6, s.), which is situated just back of the anterior 

 adductor muscle, is irregular in shape, the general form being round 

 or oval, with several depressions and plications which are stronger 

 on the inner surface. The stomach is invested by the liver (PL 6, L), 

 with which organ it is connected by the minute orifices in the 

 csecal tubes of the liver. On the right side, the stomach communi- 

 cates with a blind sac, the nature and use of which body is not defi- 

 nitely known. It varies in size at different times of the year, being 

 found most prominent after winter. Various explanations and con- 

 jectures have been made regarding the use of this organ, but nothing 

 is known with certainty. The general direction of the oesophagus and 

 stomach is toward the dorsal margin. 



The intestine proceeds from the left side of the stomach ; as soon as 

 it leaves the stomach it turns downward at an angle of a little more 

 than 45 degrees to the hinge-line (PL 6, fig. 1, i. a). 



The measurements given below are from a specimen, the body and 

 foot of which combined are five centimetres in length and three in 

 width ; of course in larger and smaller specimens, the individual 

 measurements would be different, but the comparative measurements 

 would be the same. 



The intestine proceeds from the stomach downward and backward 

 with a slight curvature till within a short distance of the posterior 

 margin of the body, a little above the foot ; it then turns toward the 

 dorsal side for a short distance, corresponding in curvature to 

 the margin of the body. At about midway between the dorsal 

 and ventral margins of the body (that is, the body proper and the 

 foot), the curvature is toward the anterior and so continues to a point 

 five millimetres below the renal organ, and a little less than two centi- 

 metres posteriorly to the stomach — .for this distance the intestine is 

 small, being about one millimetre in diameter. At this point 

 the dorsal part of the intestine is slightly prolonged and firmly at- 

 tached to the surrounding mass (PL 6, fig. 1, i. 6.). The intestine 

 here turns abruptly toward the right side and continues in that direc- 

 tion for the distance of three millimetres, then turning backward 

 and continuing just posterior to and nearly parallel with that portion 

 previously described to a point about two-fifths the length of the body 

 from the mouth, where the ventral portion is slightly prolonged and 



