24 DlSCOPHORiE. Part III. 



with a rather slender base, and, at the base of the tentacles, four-sided {Fi<^. 22), 

 with a tentacle projecting from each corner. There is a portion of the slender 

 base of the body Avhere the opposite inner walls (PI. X'\ Fig. Q b b) coalesce, and 

 thus form a solid axis, into which the digestive cavity does not penetrate. PI. X. 

 Fiff. 24 e'- is an instance of irregularity of growth in the tentacles : one of them 

 (e^) is much smaller than the others, and very transparent and thin, being evi- 

 dently stretched to the utmost, and therefore, Avithout doubt, here shown at its 

 full size. Sometimes we have found specimens which have the tentacles developed 

 in pairs (F/ff. 23) on the opposite sides of the body. Fiff. 26 is a representation 

 of a perfectly robust and flourishing embryo having five tentacles, which would 

 seem to have all developed at one time. The extensibility of the lips of the 

 mouth is here well illustrated by the large proboscis (c) formed by their expansion, 

 and Avliich is fully as plastic and active in the various shapes which it assumes, 

 and the motions which it performs, as at any later period. The degree of extensi- 

 bihty of the tentacles (e) is also better shown in this figure than in any of those 

 with four tentacles. 



In the next stage four more tentacles are introduced, at intermediate points 

 (PI. X. Fiff. 25 e) to the first four that were developed. Their mode of budding 

 is the same as that of the earlier tentacles, and they continue to grow until they 

 are as long as the first four, before another set begins to develop (PI. X. Figs. 

 33, 34, 35, 36, 37, and PI. X\ Figs. 4, 4", and 5). One of the most striking pecu- 

 liarities of this stage of growth is the hydra-like form of the embryo (PI. X. Fig. 

 33), which might readily be mistaken for a species of that genus upon casual 

 observation. The base (e^) is quite long and slender, and strongly resembles a 

 tentacle. The lips of the mouth {c) project separately, or they may be merged 

 into one and protruded as in younger stages, in the form of a proboscis {Fig. 

 35 c). The many protean shapes which the mouth may assume, render it almost 

 impossible to say what is the form of this organ ; usually, however, we find it 

 but slightly, if at all, elevated above the base of the tentacles {Figs. 34 and 37; 

 PI. X". Fig. 5), and each one of the four corners projecting toward the base of 

 a tentacle {Fig. 34; PI. X*. Figs. 1, 5, and 11). By comparing Figs. 22 and 27 Avith 

 Fig. 24 of PI. X. we find that the jjosition of the corners of the mouth is not con- 

 stant : in the first instance the corners are opposite the intervals of the first four 

 tentacles, whereas in the second they are opposite the tentacles ; and so we are unable 

 to judge whether, in the eight-armed stage (PI. X. Fig. 34), the corners are opposite 

 the first four tentacles or alternate with them. This can only Ije determined when 

 the second set of four tentacles is in an early state of development, as in Fig. 27. 

 But here we are again at fault; for if we compare Fig. 34 of PI. X. and Fig. 5 of 

 PI. X*. with Fig. 34* of PI. X., all representations taken from the same individual, we 



