RHIZOSTOMiE — lACHNOHIIIZA. iu'.i 



Among characters of minor importance the circular inuscies of the suhiimhiella are 

 entire and not hroken in the 8 principal radii. The sense-cliihs have each a sensory pit with 

 radiating furrows over its fioor. The suhgenital ostia are wider than the cohimns hetween 

 them. 



This genus is so closely allied to Crditihiour that the two might readily be merged. It 

 however, be distinguished by having no club-like appendages between the mouth-frills. 



nia\ 



Lychnorhiza lucerna Haeckel. 



Lychnorliiza lucerna, Haeckel, iSSo, Syst. der Medusen, p. 587, taf. 34, 8 fign.— Hamann, 18S1, Jena. Zeit. fur Naturw., Bil. 11;, 



p. 249 (anatomy of mouth-arms). 

 Cramhorhiza fugfllata (young metiusa), Hakckei,, Ibid., p. 646. 

 Lychnorhizri fagellulii, Vanhuffen, 18SS, Bibliotheca Zuologica, BJ. r, Hrft 3, pp. it), 42, taf. 1. fig. 7; taf. 3, fign. 1-3. 



The bell is flatter than a hemisphere, 120 to 150 mm. in diameter, and its exumbrella 

 surface is besprinkled with fine granules and minute, sharp-pointed projections. There are 

 8 marginal sense-organs and 48 marginal lappets. The 16 lappets flanking the 8 marginal 

 sense-organs are small, sharply pointed, and triangular, while the 4 velar lappets of each 

 octant are 3 times as broad and 3 to 4 times as long as those flanking the sense-organs. These 

 velar lappets are more nearly oval in outline and not quite so sharply pointed as are the ocular. 

 The 8 stout, adradial mouth-arms arise from a large, gelatinous base which projects from 

 the center of subumbrella. These 8 mouth-arms are laterally compressed, separate one from 

 another, and about as long as the bell-diameter. The outer sides of the upper halves of the 

 mouth-arms are smooth and bear no mouths, but below this the arm is developed into a ventral 

 median and 2 large lateral wmg-like membranes, all 3 of which meet at a point below. The 

 edges of these 3 membranes are much folded and are lined by numerous mouths which are 

 surrounded by minute, clubbed tentacles. In addition, the edges adjacent to the mouihs 

 bear numerous long filaments, 120 to 160 upon each mouth-arm. Near their bases these 

 filaments are conical, but they expand beyond uito a ribbon-like shape, each of the narrow 

 edges of the ribbon being lined by a row of small, club-like nematocyst-organs. Each mouth- 

 arm bears a pair of very long filaments and 15 to 20 somewhat shorter filaments, the remainder 

 being still shorter. The longest filaments exceed the length of the mouth-arms themselves. 



There is a well-developed, unbroken zone of circular muscles in the outer part of the 

 subumbrella. The central stomach is cross-shaped, the arms of the cross being in the diameters 

 of the principal radii, while the 4 subgenital pits lie in intermediate positions. 16 radial- 

 canals extend out from the central stomach: 4 in the principal radii, 4 in the secondary, and 

 8 in the tertiary (adradial) radii. The 8 principal radial-canals extend to the sense-organs, 

 but the 8 adradial ones end in the ring-canal, which is at some distance inward from the 

 margin. The ring-canal gives off 32 blindly-ending, centripetal vessels, 2 between each pair 

 of radial-canals. On its outer side the circular vessel gives rise to about 160 radiating vessels 

 (20 in each octant) which extend into the lappets and are connected by numerous, anas'omosing 

 vessels forming a marginal network. Each of the 8 mouth-arms sends a canal into the central 

 stomach. This main canal of each mouth-arm gives rise to 2 side branches, each ot which 

 extends down a lateral wing of the mouth-arm under the mouths, while the central canal 

 extends down the center of the lower side of the mouth-arm. The gonads are much-tolded 

 membranes lining the inner walls of the 4 subgenital pits. They fill the greater part ol the 

 stomach cavity and according to Haeckel, they project outward through the subgenital pits. 

 This is, however, unknown in any other rhizostomous medusa and is, I believe, mereh- a result 

 of shrinkage, etc., in the preservative fluid. 



Haeckel studied a single specimen of this medusa from Rio de Janeiro, Brazil. He 

 gives a detailed description accompanied by figures. 



I am inclined to believe that " L. flagcllata" is only the young of L. lucerna. In order 

 the more readily to aid future students in settling this question, we present a detailed description 

 of " L. flagcllata:" The disk is 80 mm. wide, about 30 mm. high, and evenly rounded. It is 

 very tough with thick gelatinous walls. The exumbrella is covered with fine granules, which 

 become larger near the marginal lappets and set themselves in elongate lines over the lappets. 

 There are 8 marginal sense-organs and 48 marginal lappets. In each octant 4 large, bluntly 

 triangular, velar lappets between 2 very small, sharp-pointed, lancet-shaped, ocular lappets 



