IIO GLOSSARY. 



PS'lypary (Gr. polus, many). The chitinous covering of the 



compound Hydrozoa. 

 Po'lypide (Gr. pttupous, many-footed). One of the zooids in 



the Polyzoa. 

 Po'lypite (Gr. polupous, many-footed). One of the zooids in 



the Hydrozoa. 

 Polyplacophora (Gr. pohis, many ; plakous, a flat cake ; phoreo, 



I bear). A group of the Mollusca comprising the chitons. 

 Polyzo'a (Gr.polus, many; zoon, an animal). A group of the 



Invertebrata, classed by Huxley with the Brachiopoda, under 



the name of Malacoscolices. 



Polyzoa'rium (Gr. polus > many ; zoon, an animal). The com- 

 pound organism of the Polyzoa. 

 Pons he'patis (L. bridge of the liver). A process of the left lobe 



which sometimes extends across the umbilical fissure of 



the liver. 

 Pons Varo'lii (L. bridge of Varolus). The mass of fibrous 



and vesicular nerve tissue which, crossing the ventral 



surface of the medulla oblongata, connects the hemispheres 



of the cerebellum. 

 Poplitae'us (L. poples, pcglitis, the inner part of the knee). An 



oblique muscle passing from the post-axial condyle of the 



femur to the tibia. 

 Poplite'al (L. poples, poplitis, the inner part of the knee, the 



ham). The name given to the arteries, veins, nerves, and 



lymphatics of the region at the back of the knee. 

 Po're a'reae. A term applied to the pores of the Echinidea, 



when scattered indiscriminately over the ambulacra! 



plates. 

 Po're fas'ciae. A term applied to the pores of the Echinidea, 



when they are arranged in bands ramifying over the 



ambulacra! and mter-ambulacral plates. 

 Pori'fera (L. porus, a passage; fero, I bear). A group of the 



Invertebrata which comprises the sponges. 

 Por'tio du'ra (L. hard portion). A name applied to the facial 



nerve by those anatomists who consider it and the auditory 



nerve as branches of the seventh pair of cerebral nerves, 



and not as, according to the most usual practice, distinct 



nerves (seventh and eighth}. 

 Por'tio mol/Hs (L.soft portion). The name given to the auditory 



nerve by those anatomists who reckon it as a branch of 



the seventh pair of cerebral nerves, instead of considering 



it as a distinct pair (eighth}. 



