This is not a common Woods Hole form. The adult medusae are square in shape and have a large manubrium which nearly fills the upper part of the subumbrella cavity. Although the young medusae have only 8 tentacles, the adults have over 100. The large, oval, red-orange reproductive organs surround the upper portion of the manubrium and are found along the four radial canals. The branching hydroid colonies are 8 to 12 mm. high and bear yellowish-red hydranths. The medusa buds are found on the stem at the bases of the hydranths.

This has not been ascertained {or the Woods Hole region. At Beaufort, North Carolina, the animals breed during the summer months.

A. Care of Adults: The adults are relatively hardy and live well in aquaria, although they are very voracious.

B. Obtaining Gametes: The eggs are shed by dehiscence from the gonads about 5 or 6 A.M.

A. The Unfertilized Ovum Approximately 20-35 eggs are shed at one time; they are spherical and measure 116 microns in diameter. The inner, dense, yellowish yolk-mass is surrounded by an outer clear ectoplasmic layer, but there is no visible fertilization membrane. Two polar bodies are produced shortly after shedding, but these soon disintegrate and are lost.

B. Cleavage and Gastrulation: Cleavage is total and approximately equal until the 8-cell stage, after which time it becomes very irregular. As in the case of Gonionemus, there is a rotation of cells at the 8-cell stage, so that a flat plate is formed. A solid, syncytial morula, with no trace of a cleavage cavity, develops in six to eight hours. Both the outer ectoderm and the inner endoderm develop from this syncytium.

C. Time Table of Development: The following time table is taken from the paper of Brooks and Rittenhouse (1907). NO indication as to the temperature is given.

Stage	Time
Polar bodies	A few minutes after shedding
First cleavage	25-30 minutes after polar bodies
Second cleavage	50-60 minutes after the first cleavage
Third cleavage	75-85 minutes after the second cleavage
Oval, morula-like embryo	6-8 hours
Free-swimming planula	11 hours
Top-swimming, contractile planula	24 hours
Attachment	48-60 hours
First hydroid well formed	72 hours

D. Later Stages of Development and Metamorphosis: The young, oval, ciliated embryo changes by the eleventh hour into a solid, bottom-swimming planula, which is elongated and has a broad anterior end. The planula continues to elongate, and after a day has the ability to contract. At this time, it becomes a top-swimmer. Forty to sixty hours after shedding, a cavity becomes visible in the endoderm of the planula, starting at the anterior end and extending posteriorly. Soon after this time, the larva again sinks to the bottom, and after a short interval, during which it glides along the bottom, the cilia are lost and the larva attaches by its side to the substrate. The root-like planula increases in size and a bud develops from the mid-region of its upper surface. Twenty-four hours after attachment, this bud becomes a young hydroid with three whorls of tentacles. The primary bud gives rise to a branching colony (much like that of Tubularia in general appearance) by asexual budding.

BROOKS, W. K., 1886. The life-history of the Hydromedusae. Mem. Boston Soc. Nat. Hist.. 3: 359-430.

BROOKS, W. K., AND S. RITTENHOUSE, 1907. On Turritopsis nutricula (McCrady). Proc. Boston Soc. Nat. Hist., 33: 429-460.