252 PROGRESS OF MICROSCOPICAL SCIENCE. 



nucleus. This second form may bo distinguished with the name of 

 Ouramoeha lapsa. Another Ouramoeba 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 Ouramoeha is 

 the same as the Plagiophrys of Claparede, though the descrij)tion of 

 this does not apply to that. Plagiophrys is said to be an Actino- 

 phryen, 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 Adinophriis. Plagiophrys is further stated to be 

 provided with a distinct tegument like Corycia of Dujardin, or Pam- 

 phagus of Bailey, but the body of Ouramoeba is as free from any 

 investment as an ordinary Amoeha, and the rays are fixed tail-like 

 appendages, with no power of elongation or contraction. The species 

 of Ouramoeba were found among desmids and diatoms, on the surface 

 of the mud at the bottom of a pond, near Darby Creek, on the Phila- 

 deljihia and West Chester Railroad. Two of the commonest sjjecies 

 of hifflugia of our neighbourhood I had until recently confounded 

 together as D. proteiformis, and, perhaps, the two forms may be 

 included imder the latter name in Europe. In one the mouth is 

 deeply trilobed, and the animal is usually green with chlorophyll 

 globules. In the other the mouth is crenulate, usually with six 

 shallow crenulations, and the animal is devoid of chlorophyll. The 

 former is usually the smaller, and may be distinguished with the 

 name of D. lohostoma ; the latter may be named D. creniilata. In 

 an old brick pond, on the grounds of Swarthmore College, Delaware 

 County, among Difflugia pyriformis, D. spiralis, D. corona, D. acumi- 

 nata, and others not yet determined, there occurs an abvmdance of 

 a large species, apparently un described. It is sometimes the fourth 

 of a line in length, and is compressed pyriform, but is quite variable 

 in its relation of length to breadth, and in the shape of the fundus 

 of the shell. This is often trilobate, but from the non-production 

 of one or more or all the lobes, differs in appearance in different 

 individuals. The animal is filled with chlorophyll grains, from 

 which it might be named D. entochloris. Another large Difflugia, 

 allied to D. lageniformis, is not unfrequent about Philadelj^hia. 

 The shell is beautifully vase-like in shape. It has an oval or sub- 

 spherical body with a constricted neck, and a recurved lip to the 

 mouth. The body of the shell opposite the mouth is acute and often 

 acuminate. The animal contains no chlorophyll. One shell measured 

 ■^th of a line long by -|th of a line broad ; another measured itli of a 

 line long by -|^th of a line broad. The species may be named D. amphora. 

 A Difflugian, found in a spring on Darby Creek, is interesting, from 

 its transparency, which allows the structure of the animal to be seen 

 in all its details. The investment is membranous and apparently 

 structureless. The soft granular contents occupy about one-half of 

 the investment, and are connected with this by long threads. The 

 pseudopods are protruded in finger-like processes. The form of the 

 animal is compressed ovoid, with the narrow pole truncate and 

 forming the transversely oval mouth. It is probably the siiecies 

 Difflugia ligata, described by Mr. Tatem, of England. Its length is 

 about ^Vrd of a line. The character of the investment is so different 



