606 RITTER. 



due to the extreme flabbiness of the test. Branchial and atrial 

 siphons about equal in size and shape, both long and strong ; 

 the lobes of each well marked — almost tumid in some specimens. 

 Thorax always much contracted, very dense, so that its internal 

 structure is made out with great difficulty. Apparently three 

 series of long stigmata in the branchial sac ; but the extreme 

 state of contraction makes certainty on this point impossible. 

 Musculature of mantle well developed, particularly as to the 

 circular fibers, these arranged in more or less regular bands, as 

 are the longitudinal ones ; the circular fibers almost as well de- 

 veloped at the posterior as at the anterior end of the thorax. 



Digestive Apparatus : CEsophagus very long and narrow ; 

 stomach nearly globular, its walls somewhat irregularly thick- 

 ened, but not distinctly folded. Post gastric intestine short, the 

 intestinal loop forming almost a circle, the stomach being situated 

 at the point where the intestine returns upon itself to produce the 

 circle. Rectal portion of the intestine very long, running closely 

 parallel with the oesophagus. 



Sexual Organs : Situated on the left side of the intestinal 

 loop, but extending slightly behind it ; ovary not voluminous 

 though the individual ova when fully grown are large ; the ovar^' 

 on the oesophageal side of the-intestinal loop, and immediately 

 behind the stomach. Testis forming a dozen or more large, dis- 

 tinct elliptical masses ; vas deferens distinct throughout its 

 length when filled with sperm. 



Embryos developed in the atrial chamber, this not produced 

 into a special incubatory pouch ; apparently about six embryos 

 and tadpoles in the chamber at one time. 



Distoma lobata n. sp. 



(PI. XX., Figs. 31, 32 and 33.) 



General Characters of Coloxv: Massive, the smaller ones 

 rather regular, thick cake-like, the larger ones ver}^ irregular and 

 prominently lobulated. Largest specimen 10 cm. long, 4 cm. 

 wide in widest part ; most prominent lobe 3.5 cm. high and 3 cm. 

 in diameter. Texture firm, but not hard. No sand imbedded in 



