158 BULLETIN OF THE 



process of self-division. Equatorially in a large otocyst a constriction takes 

 place, which later deepens until the inner wall touches the floor opposite the 

 point where the first sign of constriction appeared. The double otocyst, one ■ 

 of the component parts of which is usually smaller than the other, is now 

 separated into two distinct otocysts by the growth of the intervening margin 

 of the bell. Besides the production of otocysts by fission in this way, new 

 otocysts also appear by a gro\\'th from the ectoderm of the bell rim. 



The young of T. formosa is said by Mr. Agassiz to be without otocysts. A 

 specimen of Tima still younger than that represented in Fig. 169 of the 

 North American Acalepha; has two otocysts with otoliths, between each pair 

 of the sixteen tentacles. The number of otoliths in each of these otocysts is 

 seven. 



Many specimens of this genus were without stomachs on the end of the pro- 

 boscis. From many specimens taken in the last of May, a single example only 

 was not mutilated in this way. A new stomach, however, grows quickly from 

 the peduncle of a Tima. It forms by a process of budding in four or five 

 days, so that all the oral tentacles are fully formed at the end of that time. 

 The formation of the new stomach begins simultaneously in four points, which 

 are near the terminations of the chymiferous tubes, at the end of the peduncle. 

 As they increase in size they join at their sides, at last forming the stomach as 

 it has been described in the adult. 



Eutima gracilis, n. s. 



Plate V. Figs. 1, 2, 3, 4. 



A single specimen of a Eutima, which dififers somewhat from either of the 

 two species, E. mira and E. variabilis, described by McCrady, was taken in the 

 tow-net. It differs from these, and also from E. limjiida of Mr. Agassiz, 

 in that each of the rudimentary tentacles, as well as those fully developed, 

 bears a pair of lateral " spurs," or thread-like appendages. It may be the 

 adult of any one of the three forms of Eutima which have been described 

 from American waters, but the descriptions which have been given of them do 

 not warrant a reference of it to any one of the known species. 



The bell is shallow, rounded at the apex, and has very transparent walls. 

 The surface is smooth. The radial tubes are thread-like, and from them hang 

 small transparent sexual organs, which extend their whole length in the bell, 

 but not on the proboscis. Their undeveloped condition indicates an immature 

 individual. From the centre of the bell cavity hangs down a long, flexible, 

 transparent peduncle, along which extend the four chymiferous tubes, after 

 arching over from their radial course on the bell. The peduncle protrudes 

 outside the bell opening, and carries on its end a globular stomach, which has 

 a mouth with four oral tentacles. The hitter structures have smooth lips, are 

 undivided at the tips, and are destitute of knobs. 



The tentacles arise from the margin of the l)ell at \he junction of the radial 



