1910] Kofoid: A Revision of the Germs Ceratocorys. 179 



such as characterize the first described, most abundant and most 

 widely distributed species of the genus, C. horrida, have led 

 Schiitt (1895) to describe a Ceratocorys as Goniodoma acumi- 

 natum vet. armatum and Cleve (1903) to assign provisionally 

 another species, C. bipes, also to Goniodoma. Both are absolutely 

 typical members of the genus Ceratocorys in their skeletal or- 

 ganization, agreeing with C. horrida, the type species. 



A second reason for the confusion that has arisen in this 

 genus is the fad that the skeletal structure is profoundly ob- 

 scured, in C. jourdani by absence of well-defined suture mark- 

 ings, by small size of certain plates in other species, and by the 

 excessive thickenings ami surface pits, rugosities, spines and lists 

 which are found upon most species of this t>v nll s to an unusual 

 degree among the genera of the Peridinidae. The structures 

 obscure the suture lines ami even when the plates are parted 

 render the analysis of their interrelationships difficult and often 

 puzzling. 



GENERIC CHARACTERS. 



Ceratocorys Stein. 



Body angular or rounded, both epitheca and hypotheca often 

 flattened distally, girdle in the anterior third, girdle fins well de- 

 veloped, surface smooth or rugose, coarsely pitted, usually with 

 fins and sheathed spines along sutures. Epitheca consists of three 

 apicals about a minute apical closing plate, one intercalary upon 

 the right shoulder and five precingulars ; there are eighl girdle 

 plates, including one each at the proximal and distal ends which 

 invade the ventral area. The hypotheca consists of six post 

 cingulars, two of which at the left of the ventral area arc small, 

 one ventral intercalary just posterior to the two small post- 

 cingulars and one antapical. Skeleton retained at fission. Fission 

 plane oblique. Chromatophores yellow or brown. 



KEY TO SPECIES. 



1. With five or more long, sheathed spines with included terminal 



brushes in hypotheca 2 



1. Without long spines and terminal brushes 3 



2. Spines spreading, outline of body subangular horrida Stein 



