GEiSTUS SPHENODERIA— SPHENODERIA LENTA. 231 



and oblique or subtenninal, so that in the narrow angular view of the neck 

 it is directed toward one of the wider sides. Hertwig and Lesser, in the 

 same animal, under the name of EuglypJia globosa, describe the neck as 

 consisting of a pair of lateral points, between which the edges of the mouth 

 are cut out concavely.* 



The body of the shell of Sphenoderia lenta has appeared to me to be 

 composed of circular or oval plates, arranged in alternating rows, and over- 

 lapping at the contiguous borders, so as to give the impression of hexahe- 

 dral areas included within circles of minute elliptical areas, as represented 

 in figs. 25, 2b', 41, pi. XXXIV. Hertwig and Lesser describe the plates as 

 hexagonal, with minute, intervening, transverse, elliptical, more prominent 

 plates. f In some instances, the plates have appeared to me to be definitely 

 hexahedral, and closely adapted to one another without accessory plates, as 

 in the variety represented in fig. 34. 



The neck of the shell, between its lateral angular points, is thinner 

 than any other part, and consists of delicate homogeneous membrane, 

 extending beyond the plates of the body to the border of the mouth. The 

 latter is entire, but I have occasionally met with empty shells, in which the 

 border was divided into several lobes, perhaps the result of laceration, as 

 seen in fig. 34. 



In repeated instances I have found individuals of Sphenoderia, with 

 an oblong oval shell, having the border of the mouth divided into a num- 

 ber of minute points, as represented in fig. 40. Sometimes the points 

 appear of an irregular character, as in AssuUna seminidum. I have met 

 with several individuals of Sphenoderia, in which the shell was ovoid, 

 with the narrow pole terminated by the mouth, which had a minutely 

 denticulated border. The body of the shell was composed of accurately 

 adapted plates of hexagonal form and uniform size. In the specimens 

 previously indicated, fig. 40, the plates of the shell were circular and 

 overlapping 



The interior soft structure of Sphenoderia, and its pseudopods, are 

 identical in character with those of Trinema and Euglypha. Sphenoderia 

 nearly related with Trinema, and the variety having a denticulated mouth 

 is also nearly related with AssuUna seminulum. 



* Arehiv f. mikros. Anatomie, 1874, x, Suppl. 130. t Ibidem, 131. 



