CABYBDEID^ — CHIRODROPUS. 519 



Chirodropus palmatus Haeckel. 



Chirodropus pahnatus, H-^eckel, 1880, Syst. der Medusen, p. 448. 



This is possibly only the 3oung of a variety of C. gorilla being smaller, and only 70 mm. 

 wide and 100 mm. high, including the suspended velarium. The 2 pouch-arms which project 

 into the bell-cavity from each perradial stomach-pouch are fused together in their upper 

 two-thirds, leaving only their lower thirds free. They bear numerous filaments, as in 

 C. gorilla. Finally, each pedalium bears 21 fingers instead of 9, as in C. gorilla. 



A single specimen is described by Haeckel from preserved material found near St. Helena 

 off the west coast of Africa. 



We can not be sure that this form is distinct from C. gorilla until we know the normal 

 limits of variability of the latter species, and it seems probable that there is but a single species 

 which is somewhat variable in the number of tentacles, etc. 



Order STAUROMEDUS^. 



Lucernarida (in part), Johnston, 1847, British Zooph., p. 244, id ed. 



Stauromeduix, BLaeckel, 18S0, Syst. der Medusen, p. 363. — Goette, 1887, Abhandl. zur Entwickelungsgesch. der Thiere, Heft 

 4, p. 64. — M.^-^s, 1906, Fauna Arctica, Bd. 4, Lfg. 3, p. 499; 1907, Ergeb. Fortschitte der Zoologie, Bd. i, pp. 194, 198. 

 Lucernaridie, Gross, 1900, Jena. Zeit. fur Naturw., Bd. 33, p. 611. — Kassianow, 1901, Zeit. fur wissen. Zool., Bd. 69, p. 287. 

 Lucernariaj CLARt, 1863, Boston Journ. of Nat. Hist., vol. 7, p. 531. 



Neglecting for the moment to consider the family Tesseranthinae Haeckel, the Stauro- 

 medusae constitute a unitary group of sessile Scyphomedusae which are attached to objects 

 by means of an adhesive pad at the extremity of the aboral stalk of the bell. The bell-margin 

 usually exhibits 8 adradial lobes, the pointed ends of which terminate in clusters of hollow 

 knobbed tentacles; although in Capria we find that these tentacles are not knobbed, and 

 in the genus Stenoscyphus there are no marginal lobes, while in Lipkca there are no tentacles 

 and the lobes are perradial and interradial, not adradial. 



In the 8 perradial and interradial notches between the marginal lobes we may find a 

 knobbed tentacle, which may be metamorphosed into an adhesive organ serving as a sort of 

 anchor. In the genera Liicernaria, Ktshniouyea, Craierlophus, Capria, and Lipkea, however, 

 these anchors are not found. The central stomach gives rise typically to 4 perradial pouches 

 which are partially separated one from another by 4 interradial septa, but these pouches 

 communicate one with another at the margin, thus forming a peripheral ring-sinus. The arms, 

 or marginal lobes, are hollow, as are also their knobbed tentacles. There are 4 interradial 

 septa in the central cavity of the aboral stalk or peduncle; and these panitions may fuse in 

 the center, thus inclosing 4 separate perradial cavities in the stalk as in Haliclyslus. The 

 gonads, which are developed in the entoderm of the subumbrella, are typically interradial and 

 more or less horse-shoe-shaped with the free ends of the horse-shoe directed outward; but 

 often the horse-shoe is cleft in the middle, giving 8 adradial, crescentic gonads. There is a mar- 

 ginal ring-muscle in the subumbrella which may be entire or divided into 8 separate perradial 

 and interradial sectors. Centripetal to this ring-muscle system are the radial muscles. The 

 stalk also has a system of 4 interradial, longitudinal muscles. As in scyphostoma larvae the 

 4 interradial septa of Stauromedusae are not simple, solid-walled partitions, but each contains a 

 funnel-like pit, livid with ectoderm, which dips downward from the subumbrella thus hollowing 

 each partition. These funnel-cavities contain longitudinal muscles which extend downward 

 even to the aboral end of the stalk itself. 



Clark, 1863, and after him Gross, 1900, have made careful studies of the internal anatomy 

 of the sessile Stauromedusae. They conclude that we may divide these forms into 2 families, 

 the Eleutherocarpidae with 4 simple, perradial stomach-pouches, and the Cleistocarpidae in 

 which the neighboring halves of the adjacent gonads unite at their distal ends in the radii of the 

 corners of the mouth. Thus the gonads become united by a transverse, circumferential mem- 

 brane, which divides each of the 4 perradial stomach-pouches into 2 spaces, an outer and an 

 inner, the oral or inner one of which forms a cul de sac or confined space which contains the 

 gonads and opens at the axial end into the gastric cavity. The genera Halimocyathus, Cra- 

 ierlophus, and Depastrum are examples of the Cleistocarpidae, while Stenoscyphus, KIshinouyea, 



