498 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.45. 



pharyngeal band and the branchial orifice; the individual tentacles 

 separated from one another by a liberal interval (fig. 44, l. t.). Peri- 

 pharyngeal band low and narrow, scarcely larger than the ridge carry- 

 ing the tentacles; quite remote from the branchial orifice, making a 

 large peribranchial area which is smooth and uninterrupted except 

 by the tentacular circlet. Hypophysis mouth (hy.) rather small, 

 horseshoe-shaped, somewhat broader than long, the horns approach- 

 ing each other and directed toward the branchial orifice. Sub-neural 

 gland and ganglion forming a single elongate mass removed from the 

 hypophysis somewhat more than the length of the gland. Dorsal 

 lamina (d. I., fig. 44) low and broad anteriorly, changing gradually 

 to a high, thin membrane near the esophageal opening, then tapering 

 down rapidly to its termination some distance behind that point; 

 sides ribbed throughout; edge remotely toothed posteriorly but not 

 anteriorly. Branchial sac voluminous, not extending farther back 

 than the visceral mass; the membrane corrugated, the corrugations 

 very irregular, being neither continuous lengthwise nor of equal 

 depth. Longitudinal vessels about 25 on each side, these large 

 and membrane-like. Transverse vessels also somewhat higher than 

 thick, but much smaller than longitudinal, rather narrow and of 

 nearly the same size; distance between each two longitudinal vessels 

 nearly equaling three spaces between transverse vessels. Papillae 

 restricted mostly to the crossings of the vessels, these being proliiinent 

 and strongly curved, the concave side of the curve presenting a 

 membrane-hke expansion; intermediate papillse few, irregularly 

 scattered and small in comparison with the papillas at the angles. 

 Stigmata long and narrow, from 6 to 15 between the two longitudinal 

 vessels (fig. 45). 



Alimentary system. — Situated on left side, voluminous, occupying 

 nearly two-thirds the length of the animal and the whole depth. 

 Stomach situated at the extreme postero-dorsal angle of the body, 

 somewhat longer than broad, distinctly set off from the intestine; 

 wall with 14 or more folds sho^ving prominently on inner surface but 

 not at all on outer. Intestine proper forming a broad low reverse S 

 as seen from the outer face, the proximal limb running along the 

 ventral edge of the body from its issuance from the stomach; the 

 distal or rectal limb along the dorsal edge and somewhat farther for- 

 ward than the first loop of the intestine; anus obscurely 4-lobed. 

 Renal vesicles and concretions thickly distributed in the wall of 

 stomach and first part of intestine. 



Reproductive system. — Testes ramified over outer surface of poste- 

 rior end of stomach, and the portions of the intestine adjacent to 

 stomach. Ovary a branched structure not visible on outer surface 

 of the digestive viscera, but ramifying on the inner surface of the 

 first intestinal loop. Gonoducts not recognized. 



