39 



however, did not consider the differences great ennough to justify the estab- 

 lishment of a distinct suborder, and proposed to include the family Cytherellidae 

 within the suborder Podocopa, placing it near the family Darwinulidce. I am 

 quite unable to consent with G. W. Muller in this view, and the most recent 

 author, Dr. Skogsberg, also rejects it decidedly, fully admitting the present 

 suborder, though designing it with a new name, viz., Cytherellifotmes. 



Fam. Cytherellidae. 



Remarks. As this family at present only comprises a single genus, it 

 may suffice to give the characters of that genus. I am however by no means 

 convinced that all the fossil forms referred to it are in reality congeneric. 



Gen. Cytherella, Bosquet, 1852. 



Generic Characters. Shell of very firm consistency, highly calcareous and 

 quite opaque, being more or less compressed and, seen laterally, of oval or 

 elliptical shape. Valves very unequal, the right one being much the larger 

 and overlapping the left around all the margins; muscular spots densely crowded 

 and arranged in a double vertical row near the centre of each valve; inner 

 duplicatures very narrow, almost obsolete. Anterior antennae strongly built, 

 7-articulate, all the joints sharply defined and more or less produced in front, 

 carrying tufts of comparatively short spiniform setae, the first 2 joints the largest 

 and forming together an abrupt geniculate bend. Posterior antennae with the 

 basal part divided into 2 sharply defined segments forming together a very 

 movable articulation, rami however apparently firmly connected to the end of 

 the basal part and of somewhat unequal size, the inner one the longer and 

 3-articulate, the outer biarticulate, both rami carrying numerous strong spini- 

 form setae. Anterior lip large, and somewhat bell-shaped. Mandibles rather 

 small, with the masticatory part obliquely truncated at the end and fringed with 

 a dense row of delicate spinules ; palp sub-cylindricat in shape, almost straight, 

 and only composed of 2 joints, the distal one small, bisetose, the proximal 

 one provided at the base anteriorly with a small setiferous lamella and clothed 

 along the inner face with a dense comb-like row of delicate recurved setae. 

 Maxillae carrying at the base a very largely developed vibratory plate, and 



