GLOSSARY. 103. 



Perien'teron (Gr. peri, around ; enteron, the intestine). The 

 primitive perivisceral cavity. 



Per'ilymph (Gr. peri, around; L. lympha, water). The fluid 

 which surrounds the membranous labyrinth of the ear. 



Perimy'sium (Gr. peri, around ; mus, a muscle). The sheath 

 of connective tissue which invests a voluntary muscle. 



Perinae'um (Gr. peri, around ; naio, I am situated). The par- 

 tition between the opening of the intestine and the gene- 

 rative organs. 



Perineu'rium (Gr. peri, around ; neuron, a nerve). A term 

 suggested by some anatomists for use, (instead of neuri- 

 lemma,) to signify the sheath which surrounds an entire 

 nerve. 



Perios'teum (Gr. peri, around; osteon, a bone). The sheath 

 of connective tissue which invests the bones. 



Perio'tic cap'sule (Gr. peri, around ; ous, otos, the ear). The 

 portion of the skull which encloses and surrounds the 

 ear ; in Human Anatomy represented by the petrous and 

 mastoid portions of the temporal bone. 



Peripati'dea (Gr. peripateo, I walk round or about). A group 

 of the Arthropoda formerly classed with the Annelida. 



Peripe'talous (Gr. peri, around; petalon, a leaf). A term 

 applied to those semitse which surround the outer extre- 

 mities of the petaloid ambulacra. 



Peripharynge'al band (Gr. peri, around ; pharunx, the throat). 

 A narrow band of cilia which surrounds the pharynx in 

 some Ascidioida. 



Periphery (Gr. peri, around; phero, I bear). The circum- 

 ference. The surrounding parts as contrasted with the 

 centre. The terminations of nerve fibres in the organs 

 which they supply are termed peripheral, as compared 

 with their central terminations in the brain or spinal cord. 



Pe'riproct (Gr. peri, around; proktos, the seat or anus). The 

 space round the anus. 



Pe'risarc (Gr. peri, around ; sarx, sarkos, flesh, body). A 

 hard chitinous cuticle which in some Hydrophora sur- 

 rounds the body. 



Perissodac'tyla (Gr. perissos, overmuch ; daktulos, a finger or 

 toe). A division of the Ungulata, the members of which 

 have an odd number of toes on the hind foot. 



Peristal'tic (Gr. peri, around ; stello, I dispose). The name 

 given to the peculiar worm-like wave motion produced in 

 the intestines and similar bodies by the contraction of the 



