ON THE AFFINITIES OF THE FAMILY OF THE MEDUSA 



Cephca ocellaia. 



Fig. 35. An aperture surrounded by its membrane. 



Fig. 36. Portion of the extremity of an arm, with a young interbrachial tentacle (a). 



Fig. 37. Extremity of one of the large interbrachial tentacles. 



Fig. 38. Vertical section of a monogastric Diphyes. 

 Fig. 39. Attached ovarium. 



u. Natatorial organ. 



b. Ovisac, 

 rig- 39 a- Youngest stage of ovarium. 



a. Simple process of the common cavity. 



b, I . Ovaria further advanced. 

 Fig. 40. Prehensile organ. 



(/, b. Early stages. 

 Fig. 41. Free-swimming ovarium. 



a. Natatorial organ. 



b. Ovisac. 



Fig. 42. Free-swimming ovarium of Coryne (from Steenstrup) to compare with fig. 41. 



Sertularida:. 



Fig. 43. Cell oi Pluiiiiilaria ? 



u. Peculiar clavate organs. 



/). Large thread-cells. 

 Fig. 44. Cell of another Plumularia, letters as before. 

 Fig. 45. Ovarium of fig. 43. 



a. Organs containing thread-cells similar to fig. 43 a. 



b. Ova. 



F"ig. 46. Section of Plumularia. 



Fig. 47. Section of Polygastric Diphyes. 



Fig. 48. Section of Rhizostoma. 



Fig. 49. Section of Monostome Medusa. 



