[11] MEDUSA FROM THE GULF STREAM. 937 



socles {soc. si).). Its division from the latter is only superficial, for in- 

 teriorly its gelatinous substance is confluent with the zone of tentacular 

 socles. In the type specimen there is considerable width to this zone. 

 In live specimens it is probably not as broad, although the zone of ten- 

 tacular socles probably does not adjoin the coronal furrow, as Haeckel 

 describes and figures them in A. WyvilUi. 



2. The zone of tentacular socles {soc. ta.) is composed of twenty-two 

 gelatinous blocks, i)laced side by side, separated from each other later- 

 ally and superficially by small, shallow, radial grooves, and marked off 

 from the inner corona {i. cor.) by a ring-shaped groove {m. cor.). The 

 radial markings which separate the difierent components of the zone 

 are superficial, and the members internally form together a solid gelat- 

 inous zone. Each gelatinous block or socle bears a tentacle. The socle 

 {soc. ta.) is convex above, rounded abaxially, slightly cuneiform. Abax- 

 ially the periphery is slightly angular, with two lateral faces, and an 

 abaxial face from which hangs the tentacle {ta.). The i^ol^'hedral shape 

 of these bodies, described by Hjeckel in A. WyvilUi^ does not 'exist in 

 this species, and may in his species be in part a result of contraction. 

 The tentacles {ta.) vary in length, the longest projecting outside the 

 abaxial margin of the patagia. They are stout at the base and taper 

 uuiformlj' to the distal extremity; tentacles flexible. On the lower sub- 

 umbral side (PL II) they are fastened by two muscles with insertions 

 under the coronal muscle. Width of tentacular socle, 10™'"; length, 

 5mm_ Tentacles, 15-20™^"^ long; 4""" diameter at base. 



3. The socles of the sense-bodies [soc. sh.) are twenty-two in number; 

 they lie between the tentacular socles in the intervals on the peripheral 

 margin and alternate with the tentacles. The members of this zone do 

 not join each other. On their subumbral side lies the external coronal 

 muscle {mus. cor. e.). The plane of their upper or exumbral surface is 

 lower than that of the tentacular socles. Width, lO'""'; length, 10°^™. 

 On the medial (abaxial) part of the exumbral surface there is a brown, 

 crescen tic-shaped body, with concavity looking outward, in which lies 

 a marginal sense-body (PL III, Fig. 2). In this specimen these bodies 

 are poorly preserved. There is nothing, however, to indicate that they 

 are poorly developed, although such may be the case, as Haeckel has 

 found in his species. When the medusa is seen from the exumbral side 

 (Pi. I) only a small part of the external coronal muscle {mus. cor. e.) can 

 be seen in the intervals between adjacent socles of the sense-bodies in 

 the typical specimen. 



4. The most peripheral zone of the corona is made np of forty-four 

 thin flaps, marginal lappets, or patagia {nig. Ip.), which as a general thing- 

 are poorly preserved. Two of these arise from each socle of the sense- 

 body {soc. sb.) on the peripheral edge, and between them lies the sense- 

 body {nuf. sh.). Each patagium is leaf-like, with rounded rim. Length, 

 10'""' ; width, 5'""'. 



t::iuhumhrclla. — We recognize in the subumbrella (PL II) a large ceu- 



