114 PROCEEDINGS OF THE ACADEMY OP [1880. 



breadth of 5.5 mm. ; the height of the branchial leaves 1.25, of 

 the rhinophoria 2.0 mm. ; the breadth of the foot 3.5 mm. 



The form as usual. The head flattened in front, semilunar; 

 the tentacles compressed-cup-shaped, rather short (about 1.0 mm. 

 long), truncated at the end, longitudinall,y folded and open at 

 the outer side. The frontal margin not projecting much, with 

 many smaller and larger short digitations and crenulatious ; in 

 front in the median line were two small conical papillse before 

 the region of the rhinophoria. The margin of the rhinophor- 

 holes somcAvhat projecting, smooth : the (deeply retracted) rhino- 

 phoria with rather short stalk ; the club with thirty-five to forty 

 rather broad and thin leaves. 



The back rounded over from side to side, without certain limits 

 l)etween it and the sides of the body. At the lateral parts 

 of the back (on each side) five appendices ; the first standing a 

 little behind the end of the frontal margin; the next about in 

 the middle of the space between the first and third ; this last a 

 little before the region of the gill ; farther backwards were also 

 two similar ones. The appendices were club-shaped, with simple 

 or composite nodosities spread upon their bodies, and especially 

 at their bases ; the third was the largest, reaching the height of 

 about 2.5 mm.; all the others a little smaller, and all of about 

 the same size. Much smaller, conical or club-formed simple 

 pfipilloB were scantily and irregularly scattered on the back. The 

 gill consisting of five strong, tripinnate, quite separate leaves, a 

 single anterior and two lateral pairs. The anal nipjDle nearly 

 in the centre of the posteriorly open branchial circle, a blunted, 

 nearly cylindrical prominence, about 0.5 mm. in height ; at its 

 base on the right side and a little forwards was the very distinct 

 renal pore. The sides of the body rather high and smooth ; the 

 genital bpening a short longitudinal slit lying rather forwards, 

 with two openings at its bottom. The foot not very narrow, of 

 nearly the same breadth throughout its whole length ; the anterior 

 border emarginated in the middle, with a fine line. 



The intestines did not shine through the integuments. The 

 peritoneum was colorless, without spieula. 



, The central nervous system (PI. XV, fig. 1) flattened ; the 

 cerebro-visceral ganglia (fig. la) reniforra, a little narrower at 

 the fore-end ; the pedal ones (fig. Ibb) rounded, scarcely larger 

 than the visceral ; the large commissure (fig. 1) as usual ; small 



