CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 27 
The adult animal (figs. 42, 43, 46, plates 7 and 8) is about 100 mm. 
in length, specimens larger than this being rare. When seen from the 
narrow side, the general outline of the body is almost ellipsoidal. A view 
of the broad side, however, shows a pear-shaped outline, this being due 
to the wide-flaring oral lappets. The aboral apex is not so acute as in 
Bolinopsis infundibulum, and not so blunt as in Lesueuria hyboptera. The 
Fic. 8.—Sense-organ of Mnemiopsts leidyi. From life, by the author, 
at Newport, Rhode Island. ad, adradial canals; c, cilia at aboral 
end of stomodzeum; f, funnel or entodermal center of gastro- 
vascular system; ft, axial-funnel canal; g, paragastric canal; 
t, interradial canal; mu, connective tissue strands; p, pole plate; 
st, stomodzeum; t, tentacular canal. 
apical sense-organ (text-fig. 8) contains a mass of highly refractive con- 
ccretions, and lies at the bottom of a moderately deep cleft. The oral 
lappets are each about two-fifths as long as the entire animal and are 
even wider than they are long. The 4 auricles are flat and ribbon-like, 
and about one-fourth as long as the body of the animal. Their centrif- 
