Stenoscyphopsis vermiformis  

Body elongate and vermiform to at least 14 mm. Calyx more than 10 times longer than the stalk and tubular for about three-fourths of its length, where it is only about two times the diameter of the stalk, flaring out gradually just below the arms to about three times the diameter of the lower calyx. The eight arms are associated into four distinct interradial pairs, with the perradial notches three to four times as wide and deep as the interradial notches; each arm terminates with a cluster of 8-12 capitate secondary tentacles, the outermost 2-4 secondary tentacles on each arm share a prominent glandular cushion. Conuli, solid bodies lacking the cavity usually found in the anchors of stauromedusae, are found only in the interradial positions on the margin and may disappear with age; no conuli werre seen in the perradial positions even in very small specimens. The mouth is quadrate with folded edges. The infundibula extend into the calyx for about one-fourth of its length. The gonads consist of eight bands associated into four interradial pairs; they do not appear to be folded as in other stauromedusae. The gonads are bordered on both the inter- and perradial sides by clusters of nematocysts. Gastric filaments occur in eight rows associated into four interradial pairs and extend down about two-thirds of the length of the tubular calyx. (all from Gwilliam, 1956)

The marginal muscle is interrupted at each arm; it passes on the subumbrellar side of the conuli, where present, and is ectomesogloeal. The radial muscles are four in number in the lower portion of the calyx and each divides into two at about the level of the base of the infundibula; from this point upward to the attachment at the base of the tentacles the muscles are ectomesogloeal; where each band is single in the lower calyx, it is mesogloeal. (all from Gwiliam, 1956)

The stalk is very short and clearly separated from the calyx by a constriction; it is circular in cross section; the stalk flares at its base to form a sucker-like disc which has an invagination at the center running up into the stalk. At the level of the axial canal thus formed, the stalk is five-chambered, and above this level it is single-chambered; with well-developed bands of muscle present in the interradial septa. With a constriction at the stalk-calyx junction, which is formed by the rather abrupt narrowing of the calyx as it merges with the stalk. The pedal disc is composed of high vaculolated ectodermal cells which continue up into the axial canal, forming the lining of the canal. (all from Gwilliam, 1956)

Color in life is greenish-brown, very much like the color of the Macrocystis kelp on which it is found; there are no pigment bands or stripes, but there are scattered white flecks over the exumbrellar surface, that are groups of nematocysts and glandular cells; more prominent nematocyst clusters on the subumbrellar surface border the gonads on both the interradial and perradial sides (Gwilliam, 1956).