384 Miscellaneous. 



with tufts of tail-like appendages or rays, from which he proposed 

 to name the genus Gummceha. 



The rays project from what may be regarded as the back part of 

 the body, as the animal always moves or progresses in advance of 

 the position of those appendages. The rays are quite different from 

 pseudopods, or the delicate rays of the Actinophrycns ; they are 

 not used in securing food, nor is their function obvious. The Our- 

 amceba moves like an ordinary Amceba, and obtains its food in the 

 same manner. The tail-like rays are not retractile, and they are 

 rigid and coarse compared with those of Actinophryens. They are 

 simple or unbranched, except at their origin, and they are cylindrical, 

 of uniform breadth, and less uniform length ; when torn from the 

 body they are observed to originate from a common stock attached 

 to a rounded eminence. 



Several forms of the Ouramceba were observed ; but it is uncertain 

 whether they pertain to one or to several species. One of the forms 

 had an oblong ovoid body about ^ of a line long and jL of a line 

 broad. The tail-like rays formed half a dozen tufts, measuring in 

 length about the A\adth of the body. The latter was so gorged 

 with large diatoms (such as Kavicula viridis), together with desmids 

 and conferva?, that the existence of a nucleus could not be ascertained. 

 The species may be distinguished by the name of Ouramceba 

 vorax. 



A second form, perhaps of a different species, moved actively and 

 extended its broad pseudopods like Amoeba prineeps. When first 

 viewed beneath the microscope it appeared irregularly globular, and 

 about -jlj of a line in diameter ; it elongated to i of a line, and 

 moved with its tail-like appendages in the rear. These appendages 

 formed five tufts about ^ of a line long. The interior of the body 

 exhibited a large contractile ve-icle and a discoid nucleus. This 

 second form may be distinguished by the name of Ouramceba 

 lapsa. 



Another Ouramceba had two comparatively short tufts of rays ; 

 and a fourth, of smaller size than the others, had a single tuft of 

 three moniliform rays. 



It is possible that Ouramceba is the same as the Pkigiophrys of 

 Claparede, though the description of the latter does not apply to it. 

 Pkujlophrys is said to be an xictinophryen, furnished with a bundle 

 of rays emanating from a single point of the body ; but the rays 

 are described as of the same kind and use as those of Actinophrys. 

 Plagiophrys is further stated to be provided with a distinct tegument 

 like Corycia of Dujardin or Famphagus of Bailey; but the body of 

 Ouramceba is as free from any investment as an ordinary Amceba, 

 and the rays are fixed tail-like appendages, with no power of elonga- 

 tion or contraction. 



The species of Ourccmoeba were found among desmids and diatoms, 

 on the surface of the mud at the bottom of a pond, near Darby 

 Creek, on the Pliiladelphia and "West-Chester Railroad. 



Two of the commonest species of DiJJluyia of our neighbourhood 

 I had until recently confounded together as D. proteiformis ; and 



