GLOSSARY. 



847 



Prodeltidium — in brachiopods, the early 

 deltidium before fusion with the pos- 

 terior margin of the ventral or pedi- 

 cle valve. 



Prodissoconch — the first shelled condi- 

 tion of pelecypods. 



Produced — drawn out ; elongated. 



Proliferation — the production of nu- 

 merous zooids by budding, especially 

 when the buds arise from other buds 

 in succession. 



Proliferous — reproducing buds from 

 the calyx. 



Prolific — producing many young. 



Proostracum — the anterior portion of 

 the internal shell of Belemnoidea, It 

 is delicate, corneo-calcareous and 

 represents the forward prolongation 

 of the dorsal part of the phragmo- 

 cone. Seldom preserved in the fossil 

 state. 



Propodite — see II., 388. 



Propriodorsan — see Fig. 1231. 



Proprioventran — see Fig. 1231. 



Prosiphonate — see siphonal funnel. 



Prosogyrate — curved forward. Used in 

 reference to the umbos of pelecypod 

 shells (see Fig. 772). 



Prospect Mountain quartzite — lower 

 Cambric of Nevada. 



Protaspis — the earliest recognized stage 

 in the development of a trilobite test. 



Protegulum — the first shelled condition 

 of brachiopods. 



Pro thorax — see II., 420. 



Protoconch — the minute embryonic 

 shell of gastropods and cephalopods. 

 In gastropods, see apex in Fig. 1203, 

 c. In cephalopods, see II., 19. 



Protolenus beds — lowest middle Cam- 

 bric of the Atlantic coast. 



Protopodite — see II., 387, 



Prout limestone — middle Devonic 

 (Hamilton) of Ohio. 



Provinculum — in the nepionic stage of 

 many pelecypods, the primitive taxo- 

 dont hinge ; this is apparently inde- 

 pendent of the permanent dentition 

 which begins later by the develop- 

 ment of laminae on the hinge plate 

 (see also I., 363). 



Proximal — nearest the body or center. 



Pseudo — a prefix meaning false. 



Pseudocolumella — in corals, the false 

 column formed by a twisting of the 

 septa at the center of the cup (see I., 

 48). 



Pseudodeltidium — the convex plate 

 formed by the union of the deltidial 

 plates. Usually easily distinguished 

 from the true deltidium by the ver- 

 tical growth lines (see Fig. 432). 



Pseudo-fossulce — see L, 48. 



Pseudo-plankton — an organism which is 

 normally or only in early life ben- 

 thonic, but later drifts about aim- 

 lessly, either free or attached to a 

 floating object (the latter also called 

 Epiplankton) . 



Pseudo-septa — in certain Bryozoa, the 

 ends of the lunaria projecting into 

 the cells (see Fig. 182, a, f). 



Pseudotheca — the false wall of a coral 

 formed by the thickening and fusion 

 of the outer ends of the septa. 



Punctate — dotted ; with scattered pits. 



Pustule — a small, blister-like elevation. 



Pustulose — bearing pustules or blisters. 



Put-in-Bay limestone — lower Monroan, 

 Michigan, Ohio, etc. 



Pygidium — the posterior or tail portion 

 of the carapace of trilobites (see 

 Figs. 1542, 1585, 1586). 



Pyramidal — in the form of a pyramid. 



Pyriform — pear-shaped. 



Quadrangular — four-angled. 



Quadrant — a fourth pairt ; the quarter 

 of a circle. 



Quadrate — with four equal sides and 

 four right angles ; a square. 



Quadri — a prefix, meaning four. 



Quadrifid — Cut into four parts. 



Quartermaster formation — Permic of 

 northern Texas. 



Quebec group — Cambro-Ordovicic com- 

 plex of Canada. 



Queen Charlotte formation — Coman- 

 chic of Queen Charlotte Islands. 



Quincunx — an arrangement of five ob- 

 jects with one at each corner of a 



