500 PROCEEDINGS OF THE ACADEMY OF [May, 



thick ventral lobes. There is a pair of slight lateral emarginations, but 

 no well-marked incisions. 



Except at the rounded peristomium the body is depressed. It in- 

 creases in width to the end of the thorax, from which point it diminishes 

 very gently to the posterior one-tenth or beyond, and then very rapidly 

 to the small pygidium, on each side of which is a conspicuous cluster 

 of numerous brown pigmented eye-spots. There are 8 setigerous 

 • thoracic and 107 abdominal segments. The coalesced peristomium 

 and first setigerous somite are about twice as long as succeeding somites. 

 Besides the collar they bear an undivided, very thick ventral plate, 

 which is about twice as long and much wider than any succeeding 

 thoracic plate, but about equal in the latter respect to the first abdomi- 

 nal. The remaining thoracic plates are about equal in length, but 

 from the third, which is the narrowest, they increase gradually in 

 width to the last. Owing to lateral extensions anterior to the unci- 

 nigerous tori, the margms of the ventral plates are strongly serrated. 

 The abdominal ventral plates are also thick and occupy about three- 

 fifths of the ventral area. Widest at the anterior end, the first 15 or 

 20 become gradually narrower, after which there is no change until at 

 the posterior end of the body they diminish correspondingly. Through- 

 out they are sharply defined by straight margins. In the alcoholic 

 specimens all of the segments are short and sharply defined, and an 

 " extensive area on the dorsal surface is thrown into very deep rugous 

 glandular folds, occupying on the posterior one-third of the type speci- 

 men the entire width of the dorsal area, but anteriorly becoming lower 

 and more and more restricted to the middle region imtil they finally 

 fade out. On the second specimen they are less conspicuously devel- 

 oped, but are otherwise similar. A well-marked f a cal groove divides 

 the abdominal ventral plates into equal halves to the first, cuts this 

 obliquely to the left and passes dorsad in the thoracico-abdominal 

 groove to the level of the abdominal setaj tufts, and then obliquely 

 across the last thoracic somite dorsal to its setae tuft to the middle line, 

 along which it proceeds as a deep and conspicuous groove to the dorsal 

 collar openmg. 



All setae tufts are large and prominent, the abdominal strictly verti- 

 cal and ventral, the thoracic dorsal and slightly ob'ique, except the first, 

 which is nearly horizontal, entirely free from the collar and sliglitly 

 smaller than the others. The imcinigerous tori are also well marked, on 

 the thoracic i^omites meeting the ventral plates below and slightly 

 hooked backward above. The first pair, on the second setigerous 

 somite, are the longest; the seventh and last about three-fourths as 



