.\\TJIO\IL IMS K |'|;IP|:I.^< HiAiTM.A. 



The fourth set of radial-canals (4444, fig. 100, iv) arise from the sides of the second set of 

 canals. At the completion of this stage, the medusa has 16 canals and 16 marginal tentacles 

 which are about 22 30' apart. This docs not occur until the medusa is about $.5 mm. 

 in diameter (plate 20, tig. 4) and some individuals appear to In-come sexually mature before 

 this stage is reached (plate 20, tig. j). 



This medusa is common in Narragansett and Buzzard's Bays on the southern coast of 

 New England. It is rare, according to Brooks, at Beaufort, North Carolina. McCrady found 

 a single mature specimen and I have found several in Charleston 1 1 arbor. South Carolina, and in 

 the Bahamas and Tortugas. It has not been taken north of Cape Cod on the New Kngland 

 coast, but is found along the entire coast of North America from the Bahamas to southern 

 New England. Bigelow, 1909, has demonstrated that there is a closely related budding 

 variety in the tropical Pacific. 



It is possible that " Dicranocanna furcillata," found by Ilaeckel off the Atlantic coast of 

 Morocco, may be identified with P. ornnta. 



From South Carolina southward our I', rinnitii gives rise to a \arietv which produces 

 medusa-buds upon stolons at the 4 radial corners ot the stomach near the points of entrance 

 ot the 4 radial-canals, and Haeckel's medusa has stolons in these 



Proboscidactyla ornata var. stolonifera Bigelow. 



(?) Williia, s/i., HIDCLFV, 1877, Manual of AM.IMHI, nl Invertebrate, I Animals, London, p. 120, fig. 17. 



(?) Proboscidaclyla tropica, BROWNE, 1904, Fauna and Geog. "I M.iUiu- ami I. ana, In.- \u hipeljjjoe-, \.,l. 2, part }, Hv,lr,>- 



meilusii-, p. 727. 

 Preboscidactyla ftavtctrrtit f i Tar. aolonifera, MAAS, iijo^, Cr.ivpeilnten Me,kisen ,ler .ViV'^/j Kipe,liti<>n, p. 21, taf. 4, fign. 24-28; 



1906, Revur Suij-st- ,le /no]., liinit- 14, p. 89. 

 Pryboscidaclyla omtita, vnr. stohniffiii, Bigelow, H. B., 11)09, Mt-tn Mus. Cnmp. X.uol. .it H.irvar,! College, vul. ^7, p. 220, 



plates 6, 41. 



Bell rounded, 5 mm. wide, 4 mm. high, with a low, dome-like, apical projection and 

 thin walls. 12 to 20 or more tentacles, one at the base of each terminal branch of the 4 main 

 radial-canals. These tentacles are about as long as the bell-radius and have large, spherical 



basal bulbs which bear entodermal 

 pigment-granules. An equal number 

 ot meridional lines ot nematocysts 

 alternate with the tentacles. These au- 

 upon the exumhrella and extend trom 

 the margin about one-tilth to one-halt 

 the distance up the sides ot the bell. 

 There are a number ot clusters ot net- 

 tling cells upon each line. The axial 

 line is composed ot a core ot ento- 

 dermal cells which branch off trom the 

 solid cord ot entodermal cells which 

 constitute the degenerate "ring-canal." 

 The 4 mam radial-canals branch 

 quite irregularly after the second fork- 

 ing, so that 12 to 20, or more, canals 

 reach the margin. The general mode 

 ot forking is, however, similar to that 

 of /". rjniiitti. 



Medusa-bearing stolons develop 

 at the second and thud tm kings ot 

 each of the 4 radial-canals. There are thus 8 of these stolons, 2_in each quadrant. These 

 stolons do not all develop at one and the same time. The two oldest appear at the second 

 forks of the canals of one diameter, then the next two at the second folks ot the diameter 

 90 apart from the first, and then the 4 others follow in the same order at the third fork- 

 ings of the canals. 



The stomach is wide, cruciform, and urn-shaped, as in other species ot the genus. I he 

 4 lips are recurved, and the manubrium is not longer than one-half to two-thuds the depth 



Fin. toi .Proboscidoclyla orntiin i-ar. stolonifrrti, after M.i. iv, in 

 Hr^t-h. Xihogit KxpeJ., Mnnog. X. 



