682 BEEP WATEB MOLLUSKS AND BBACHIOPOBS—BALL. vol.xvii. 



face, is evidently capable of being greatly distended. It lias a smooth, 

 rather tougli, lining without any horny appendages, and is lubricated 

 by the discharge of several muciparous glands of rather small size. 

 Its inner end is abrupt, and at the left of the middle line is the open- 

 ing of the oesophagus, very much smaller than the pharynx in diame- 

 ter. The proboscis proper is very short (in spirits), only about one-sixth 

 as long as the pharynx, and therefore, unless capable of great exten- 

 sion in the living state, probably can not be extruded from the oral 

 oi3eiiiiig. The pharynx of the specimen examined was partly filled with 

 a dark-greenish matter, apparently of a mucous character, which 

 showed no traces of organization, leading to the supposition that the 

 pharynx was adapted to the engorgement of large masses of proto- 

 plasmic matter rather than the pursuit of living animals of a higher 

 order, as in most Toxoglossa. The modification is analogous to that by 

 which Turcicula, a derivative from a phytophagous stock, has become 

 adapted to gorging itself with large quantities of foraminifera, algae 

 being absent from its habitat. The tooth sac opens near the end of the 

 proboscis, but being filled with coagulated mucus, and extremely 

 reduced in size by degeneration, could not be discovered until the mass 

 was boiled in caustic potash in the hope of finding some traces of teeth. 



The teeth are set regularly in a single row on each side of an 

 epithelial strip of rather horny (not chitinous) consistency, the points 

 of the teeth inclined obliquely inward and overlapping a little. The 

 width of the radula from base to base of the opposite teeth is ^25 of 

 an inch. The length of the developed radula is about -o^ of an inch. 

 There are forty or more developed teeth in each row, besides ten or 

 twelve undeveloped germs of teeth. The fully developed teeth are 

 2^0 of an inch in length and about one-fourth as wide as long. This, 

 for a creature over 4 inches long when extended, seems very minute. 

 The form of the teeth is much like that of Bela; they are sharply 

 pointed, translucent, and composed of a plate like the die for a steel 

 pen folded closely upon itself with a U-shaped section. The shaft is 

 set in a chitinous yellow socket, which is extended on the back of the 

 tooth so as to form a little hooked knob; opposite this many of the 

 teeth show a small sharp basal denticle. The anterior arm of the U is 

 shorter than the other and obliquely trimmed ofi' toward the apex of 

 the fang. There is a well marked oval poison gland, about 2.5 mm. 

 long, with a slender duct folded twice upon itself, very tortuous, and 

 about 15 mm. long. Behind the proboscis the alimentary canal con- 

 tinues of moderate size for nearly a whorl, when there is an incon- 

 spicuous enlargement corresponding to a stomach, with its inner walls 

 longitudinally wrinkled and no marked pyloric curve. It contained 

 merely mucus, and resembled a slight enlargement of the esophagus 

 rather than a well differentiated stomach. 



The upper portion of the animal could not be extracted from the 

 spire in spite of all efforts, and so great an advantage in this respect is 



