NIAGARA FALLS AND \'ICIN1TY 2/1 



paddles — large or last pair of thoracic legs of the euryptcrids 

 pallial line — line on the interior of the shell of mollusks marking the at- 

 tachment of the mantle 

 pallial sinus — reentrant angle in the pallial line usually at the posterior end 



of the shell of pelecypods; it marks the attachment of the siphon 



muscles 

 palmars — third series of brachial plates of the Crinoidea, lying above the 



axillary distichals 

 palmate — palm-shaped 

 palpebral lobes — supra-orbital extensions from the fixed cheeks of trilo- 



bites 

 papilla — a small nipple-shaped protuberance 

 papillose — covered w^ith papillae or fine projections 

 parabasals — second cycle of basal plates in crinoids 

 pectinated rhombs — paired pore clusters in the calyx of certain cystoids 



(Callocystites) 

 pedicle — fleshy peduncle or stem used for attachment in the brachiopoda 

 pedicle valve — valve which gives emission to the pedicle in the brachiopoda. 



Ventral of most authors. Usually the larger valve 

 pentameroid — live chambered, similar to Pentamerus 

 pentapetalous — resembling a five-petaled flower 

 penultimate — next to the last 



periderm — outer chitinous covering of Hydrozoa 

 periostracum — epidermis or outer organic coating of shells 

 peripheral — pertaining to the circumference 

 peristome — margin of an aperture, i. e. the mouth of a univalve molluscan 



shell, the mouth of a bryozoan cell, etc. 

 peritheca — epithecal covering which surrounds a colony of corallites, i. e. a 



compound corallum 

 petaloid — resembling a leaf or petal 

 pinnate — shaped like a feather 

 pinnulate — provided with pinnules 

 pinnules — finest divisions of the arms of crinoids 

 plano-convex — normally in brachiopods, with the pedicle valve convex and 



the brachial valve flat 

 pleura — lateral portions of the thoracic rings of trilobites 

 plicate — plaited or folded 



plications — folds or rib-like plaits of a brachiopod shell 

 polyp — animal of a simple coelenterate or bryozoan 

 polypite — individual polyp of a colony 

 pore-rhombs — pore clusters, arranged in rhombic manner in the calyx of 



cystoids 

 poriferous — pore-bearing, corals which like Favosites are furnished with 



several pores • 



posterior — situated behind 



