86 PROCEEDINGS OF THE ACADEMY OF [1880. 



The color of the animals preserved in spirits was uniformly yel- 

 lowish. The length was 13-15.0 mm., by a breadth of 8.5-9.5 and a 

 height of 4-5.0 mm.; the breadth of the foot 6 mm.; the height of 

 the rhinophoria about 2.5 mm., of the branchial leaves 1.0-1.3 mm. ; 

 according to M. Sars the height of the rhinophoria is four to five times 

 that of the tubercles of the back, (1. c. p. 16, also in one of his figures 

 fig> 7). The form as usual ; the back .covered all over with large 

 rounded tubercles, which rose to the height of 1.5 mm., and were of 

 a similar breadth ; they were sessile or more or less subpedunculate, 

 sometimes set in indistinct longitudinal rows ; between the larger 

 tubercles everywhere were smaller ones of different sizes ; on the 

 margin of the back were tubercles of middle size or smaller ; the 

 spicula rather indistinct between and in the tubercles. The rhinophor- 

 openings as usual, two large tubercles before them ; the club of the 

 organs with about twenty-five leaves. The gill with eight to twelve 

 leaves ; according to M. Sars, the number of branchial leaves is ten — 

 to LovL'n, eight to ten. A large (high) tubercle between the hindermost 

 leaves, before it the low anal papilla, and to the right side the renal 

 pore ; some few smaller papillae were spread over the space between 

 the anus and the branchial leaves The head large, broad ; the short 

 tentaculje pointed. The genital opening as usual. 



Six individuals were dissected. The peritoneum was colorless. 



The central nervous system rather flattened, especially the visceral 

 ganglia, which lay on the outer side of and behind the cerebral ones', 

 which were a little larger ; the pedal ones larger than either of the 

 other ganglia, situated perpendicularly upon the former. The proxi- 

 mal olfactory ganglia bulbiform, a little smaller than the buccal ones ; 

 no distal could be found. The length of the commissures equal to the 

 largest diameter of the pedal ganglia ; the subcerebro-pedal about 

 three times as thick as the visceral. '! he buccal ganglia of oval form, 

 connected through a short commissure ; the gastro-oesophageal about 

 one-sixth of the former in size, with one very large cell. 



The eyes with black pigment, yellow lens ; the nervus opticus about 

 as long as the largest diameter of the cerebral ganglion. ']"he otocyst* 

 of the same size as the eyes, situated externally at the junction of 

 the cerebral and the visceral ganglia ; with about fifty ordinary 

 otokonia, but among them four to six larger ones, of a diameter of 

 about 0.025 mm. The leaves of t^e rhinophoria nearly without 

 spicula ; in the axes, and especially in the stalks, on the contrary, an 

 enormous quantity of large spicula, in great part transversely situ- 



