Chap. II. AURELIA FLAVIDULA. 39 



iu a lateral direction ; but in profile the upper and lower sides are only slightly 

 convergent outward. They are not attached to the disk at right angles to its 

 surface, but obliquely and by the ujjper side, so that the base of attachment is 

 as broad centrifugally as transversely. By this mode of attachment the peduncle 

 projects outward {Fig. 33 h), and not downAvard, and turns up at the end, so that 

 the eyes {Fig. 3-4 h) may survey the upper surface of the disk.^ 



The most distinctly marked features in the next stage which we have observed 

 are the first appearance of the tentacles (PI. XP. Fig. 2 i^), and the addition of 

 another row of genital appendages {Fig. 1 g^). The manner of the development 

 of the first tentacle is very simple : the outer and inner walls {Fig. 2 i^ i*) of 

 the marginal lobule bud out together, and form a papilla {i^), or hollow vesicle, 

 with a double wall. Near the base of the tentacle, inwards, the outer {i^) and 

 inner walls («'*) of the body are separated from each other for a considerable distance, 

 and, just below the tentacle, the outer wall (/^) projects in the form of a thin, 

 broad, hollow tongue (/), which extends nearly across the whole interval between 

 the oculiferous lobes (/), and is about one fifth longer than the basal breadth. 

 This constitutes the marginal veil. The second row of genital ai^pendages {Fig. 

 1 g^), which are eight in number, are arranged in a curved line, at a short distance 

 exterior to the first row (^^) ; they all communicate with a narrow, curved furrow, 

 {g^) which runs parallel to the broad furrow {g^) of the first row {g'). The wall 

 of each appendage varies in thickness to a considerable extent, according to the 

 state of expansion or contraction of this organ. On account of the superior length 

 of the appendages of the first row, they at times appear as if they were situated 

 exterior to those of the second row; but they may very easily be traced to their 

 origin nearest to the proboscis. Finally, the chymiferous canals {Fig. 2 e) have 

 united Avitli each other at their peripheric ends by means of lateral passages (e^), 

 and thus the marginal chymiferous canal is formed. But we will give more details 

 of this system in the description of the following stage. 



In the next phase (PI. XP. Figs. 3, 4, 4% 7, 8, 9, 11, 12, 14, 15, 16, and 16^), 

 a more decided advance in development than in the last has been made, the most 

 striking feature of which is the appearance of a broad, concentrically folded band 

 {Fig. 4 m vi^), which corresponds to the circular muscular band of Cyanea (PI. IV. 

 Figs. 1 and 2 d d^). The general outlines and proportions of the disk have not 

 materially changed since the last two phases, excepting that the marginal veil 

 (PL XP. Fig. ii i) has become very prominent as a portion of the periphery, and 

 occupies the whole breadth of the interval between the oculiferous lobes (/). The 



^ The peculiar position, mode of attachment, and fuller illustrations when we come to a little older 

 structure, of these organs, will be described with phase. 



