18*79.]] NATURAL SniENCES OF PHILADELPHIA. 83 



on the lateral part of the back along the papillae yellow vessels 

 (hepatic ducts?) shining through the walls of the back. Accord- 

 ing to Cooper the length of the living animal reaches about one 

 and a half inch. Hall's specimens were only about seven lines in 

 length. 



The length of the individuals preserved in spirits was about 

 12. 5-1:5.0 mm. by :i breadl h of I -4.5, and a height <>(' :; 4.25 nun. ; 

 the length of the tentacula was about 2.5-3.0, of the rhinophoria 

 2.5 mm., that of the papillae reaching 4.0 mm.; the breadth of the 

 front part of the foot 4.0 mm.; the length of the produced angles 

 about 2 mm. The color was uniformly brownish-white ; the intes- 

 tines nowhere shining through the skin. 



The head is rather large, the tentacles long and strong, the oral 

 aperl lire as usual ; the rhinophoria are strong, the club with about 

 twenty to twenty-five leaves. The hack is rather broad; the pa- 

 pillae set in transverse or oblique rows, that were; crowded in 

 about four groups. The first group of papilla- is the largest of 

 all, compressed horse-shoe shaped, with about five to seven 

 oblique rows in the foremost, and four to live in the hindmost 

 limb; the number of papillae in the rows seemed not to surpass 

 ten or twelve. The second group had about six to seven oblique 

 rows; the number of papillae in the rows seemed not to exceed 

 eight or nine. The spaee between the first and second groups 

 was larger than that between the second and third, in the upper- 

 most, part of the latter space is the rather prominent, goblet- 

 formed or more applauafe anal papillae; more forward and down- 

 ward was the renal pore, which in one individual was rather 

 prominent. The Hard group on one (right) side composed of 

 several (five to seven), on the other of fewer (three to four) 

 rows, but never very distinct from the fourth group, which had 

 about ten to fourteen densely set rows, which by degrees decrease 

 in size backwards and cover the whole of the rest of I he side parts 

 of the back; sometimes the rows of this fourth group stand in 

 pairs; the innermost parts of the rows are separated by very nar- 

 row spaces. 1 The papillae conical, somewhat contracted in the 

 inferior parts. The sides not low; the genital papillae in the usual 



1 The state of conservation of the individuals did not permit, are to ascer- 

 tain the relations of the groups and the rows with full certainty, so much 

 the more as the greater part of the papilla- bad dropped off. 



