76 OPISTHOBRANCHIATA OF BRAZIL 



0.099 mm. The outermost tooth in each row is much smaller 

 than the average, the base being much shorter, often nearly rudi- 

 mentary, and the hook much more slender, as is shown in the 

 slightly oblique view in fig. 69 of PI. XIII. The next two teeth 

 adjacent to the outermost, are progressively larger and form a 

 transition to the remainder in the row. In like manner the inner- 

 most tooth of each row (PI. XV, fig. 76) is much smaller than its 

 fellows, the succeeding ones increasing in size, the typical dimen- 

 sions being reached in the fifth or sixth tooth of each series. 

 In front view all of the teeth of the radula are inclined toward 

 the median line by a strong curve at their bases, the effect of 

 which is partly nullified by a curve in the reverse direction in the 

 middle and upper portion of the shaft (PL XIII, figs. 67, 68). 



Visceral complex. The esophagus begins with a large dila- 

 tion immediately behind the pharyngeal bulb. It recurves upon 

 itself, narrows, passes through the commissural loop of the central 

 nervous system, and, after a short course, opens into the stomach. 

 The posterior visceral mass is bluntly conical, 8.0 mm. long by 

 5.5 mm. in maximum diameter, its lateral and lower surfaces 

 convex, the upper one slightly flattened. The upper anterior mar- 

 gin is deeply notched for the reception of the stomach, the pyloric 

 flexure of which is uppermost, passing gradually backward into 

 the wide intestine, which courses along the dorsal surface of the 

 liver to the anus. At the left of the pylorus lies the sack-like 

 gall cyst of the liver, the greatest diameter of which, 1.4 mm., is 

 nearly equal to that of the pylorus. 



REPRODUCTIVE SYSTEM. 



Hermaphroditic gland and duct. The hermaphroditic gland 

 lies as usual upon the upper and anterior portion of the liver. 

 The slight development of the reproductive cells rendered this 

 gland relatively inconspicuous in the specimen. The hermaphro- 

 ditic duct is short and slender, passing forward from the right 

 anterior lobe of the hermaphroditic gland, and, after a course of 

 ca. 1.5 mm., dilates into the long thick convoluted hermaphroditic 

 ampulla (PL XIV, figs. 73, 74, h. amp.}. This is closely coiled 

 in a number of loops upon the posterior and lower border of the 

 anterior genital complex, and makes up fully one-third the bulk 

 of the latter. Its approximate length is 7.0 mm., with a fairly 



