873 



Foramen — an opening or pore; specifically the opening for 

 the pedicle in the pedicle valve of the Brachiopoda. 



Fossula—a groove in the calyx of a coral, usually due to 

 the abortion of a .septum. 



Frond— the foliaceous or leaf-like expansion of the skeleton 

 of Bryozoa and other organisms. 



Genal spines— the posterior prolongations, or spines, of the 



free cheeks of Trilobites. 

 Gibbous — swollen or humped. 

 Glabella — the central, most prominent, portion of the Trilo- 



bite cephalon, bounded by the fixed cheeks. 

 Gonopolyp — the reproductive polyp of Hydrozoa. 



Hexacoralla — a class of corals built on the plan of six. 

 Hinge area — the flat area bordering the hinge line of many 



Brachiopods. 

 Hinge line — the line of articulation. 

 Hydrotheca — the cup enclosing the nutritive polyp in the- 



caphore Hydrozoa. 

 Hyponome — the water tube, or squirting organ, of squids, 



cuttlefish, and other Cephalopods. 

 Hypostoma — the underlip of the Trilobites, usually found 



detached. 



Imbricate — overlapping serially. 



Implantation — planting between, as a new plication sud- 

 denly appearing between two older ones. 



Inarticulate — not articulating by teeth and sockets; of 

 Brachiopoda. 



Incised — cut into. 



Infrabasals — the lower cycle of basal plates in the Crinoids 

 with dicyclic base. 



Infun dib uliform — f unnel-shaped . 



Inosculating— connecting, so as to have intercommunica- 

 tion . 



Interambulacral — between the ambulacra. 



