Post-jKjliiu-irs — all the plates superior to the axillarv pal- 

 mars in the arras of Crinoids. 



Proliferous — re])ro(liicin,u' Imds from the calyx. 



Protoconcli — the emlH-yoiiic shell of a cephalous molluscan. 



Pseudo-colmnelhi — false coliiraella in corals, formed l»y a 

 twisting of the septa . 



Pseudo-deltidiuin — false deltidinm {Sjtirifer), formed by union 

 of the two deltidial plates. 



Pseudo-septci — septadike ridges of ChtBtedes, etc.; the 

 projecting ends of the lunaria in the cells of certain 

 Bryozoa. 



Pustulose — bearing pustules or projections. 



Pygidium — the posterior or tail-])ortion of the carapace of 

 Trilobites. 



Pyriform — pear-shaped. 



Quadrifid — cut into four points. 

 Qundrilohnte — bearing four lobes. 



Riichis — the central stem of a frond in Bryozoa. etc. 

 Radinls — the main plates of the calyx of a Crinoid, resting 



on the para-basals, and alternating with them. 

 Radii — the ribs or striations diverging from the l)eak of a 



shell. 

 Ramose — branching. 

 Reticulated — hke a network. 

 Retral — back ward. 



Rhynehonelloid — resembling Rhynchonella. 

 Rugosa — an old name for the Tetracoralla. 



Saddles — the forward bending portions of the suture in the 



shells of Cephalopods. 

 Scalar — small transverse plates in the genus Unitrypa of the 



Bryozoa ( which see). 

 Scalariform — stair or ladder-shaped. 

 Sclerenchynia — the calcareous tissue deposited by the coral 



polyps. 



