[45] MEDUSiE FROM THE GULF STREAM. 971 



the edges of tlie two ptera, fitting closely upon the axis of the animal, 

 recall the edges of the foot of a Gasteropod mollusk.* 



It is difficult to determine definitely the function of the ptera and the 

 ])eculiar strncture of the polypites of Fterophysa unless we study the 

 animal alive. The direction of the coiling by which a muscular surface 

 is brought on the concavity of the polj'pite, and. the appearance of the 

 ptera, suggest that the polypite in Pferophysa is specialized into a grasp- 

 ing organ, and that these are sucker-like structures by which it lays 

 hold of a foreign body. 



The power of grasping by means of the polypites and tasters is a func;- 

 tion not unknown, in a limited degree, among other Siphonopliora. 

 Both R. filiformis and R. Eysenhardtii wind their polypites about a pen- 

 cil thrust near them, while PhysopJiora Jiydrostatica, Forsk. will, in the 

 same way, grasp a foreign body with its tasters, as one can easily see 

 by worrying them or by placing a pencil in their immediate vicinity. 

 There are, however, in neither of these genera no ptera on tlie polypites 

 and tasters, as in the genus Fterophysa. We can, therefore, conclude 

 that Pterophysa has the same or a similar power of grasping in its poly- 

 pites, and that the modification in the structure of the side of the feed- 

 ing-stomachs with the two lateral wings point to that function. Wind- 

 ing themselves about a foreign body, it probably fastens itself by means 

 of the sucker-like side of the polypite. In this way we are tempted to 

 suppose that it may even drag itself along from place to place on the 

 floating body to Avhich it has attached itself. By the same specialized 

 region of the polypite it may grasp its food, and it is a suggestive fact 

 in this connection that I was unable to detect any tentacles in either of 

 the specimens of Pterophysa which was studied, 



AXGELID.E, fam. nov. 

 Angelopsis, gen. nov. 



(P]ateX, Figs. 4, 5.) 



The genus AtigeUi., discovered by Rang and figured and described by 

 Lesson, has never been retaken, and nothing has been added to our 

 general knowledge of the genus since the first mention. The statement 

 of Professor Huxley expresses the present condition of our knowledge 

 of Angela, as it did twenty-five years ago when the now classic "Oceanic 

 Hydrozoa" was written. He says, "All the author of this genus really 

 knows of it is, he says, derived from a drawing ' Communique par M. Rang 

 sans nom et sans reseignements.' Under such circumstances it is hardly 

 worth while quoting his definition." While speculation in regard to 

 Angela as defined by Lesson, from the imperfection of our knowledge (it 

 must be acknowledged that Lesson's figure has some value), must neces- 



*I was remincled in studying the form and relationship of the ptera to the poly- 

 pites in Fterophysa of similar structures in the modified leaf extremity of Xephe'nthes 

 and other "pitcher plants." The resemblance is a distant one, and pertains only to 

 the lateral appendages to the pitcher-like leaf. 



