GLOSSARY. 



agreeing with the Belluw of Linnseus. Of its members the Elephants now 



form the order Proboscidia, the Hyrax Hyrauridea, and the remainder may be 



called Ungulata, the artiodactylous genera uniting with the Ruminants. 

 PALSXJTHERIUM (ira\a.i6s, ancient ; Oypiov, beast), a Tapir-like ungulate mammal 



of the Tertiary epoch. 

 PALLIUM (a cloak), the " mantle " of Mollusks, an extreme development of the 



integument, represented in its epithelial, vascular, glandular, and muscular 



structure, with folds and processes forming the " foot " and other appendages. 

 PAUASPHENOID (irapd, beside ; <r<f>r]voei5ri?, wedge-shaped), a long azygos bone 



which runs from before backward under the base of the skull in Ichthyopsida 



and some Reptiles : so called from its relation to the sphenoid bone. 

 PARENCHYMA (jrapeyxvfj.a, fr. irapd, fv, x>, something poured in beside), applied 



to the proper substance of viscera, excluding connective tissue, blood-vessels, 



and other accessory parts. 

 PAUIETAL (parietes, walls), the upper ossifications in membrane of the second 



cranial segment. 

 PARIETO-SPLANCHNIC ( parietes, <nr\dyxva, the viscera), a ganglion in the higher 



Mollusks which supplies the mantle, gills, and viscera. 

 PARTHENOGENESIS (irapQevos, virgin ; yeveans, generation), asexual reproduction, 



either by fission, gemmation, or the process of internal budding best seen in 



the Scolecida, and called by Quatrefages " Genea-genesis."' 

 PATAGIUM (iraTayelbi/), a stripe or border to a dress ; applied to the expansion of 



the integument by which bats, flying squirrels, flying lemurs, &c., support 



themselves in the air. 

 PATJROPUS (VaDpor, few ; irous, foot), a genus of Myriapoda intermediate between 



the two orders represented by the Scolopendridas and lulidae. 

 PECTOSTRACA (irij/criJs, fr. ir-fiyvvfj.i, fixe.1, compacted ; offrpautov, a shell), an order 



of Crustacea, which become fixed in the adult state, including the Cirripedia, 



and Rkizocephalus with its allies. 

 PELVIS (ireAjy, ireAus), a basin, applied to the " hip-girdle " or bony arch supporting 



the lower extremities of most Vertebrata : it consists of the sacrum (formed 



of two to five vertebrae), the ilia or haunch bones, pubes, and ischia. 

 PENTASTOMA (TreWe, five ; o-r^a, mouth), a name given under a wrong conception 



to a genus of parasitic habit, otherwise called Linguatula, which gives its 



name to an order of Arachnida. 

 PERICARDIUM (irepi, around ; /capSja, the heart), the membrane which surrounds 



the heart : in Crustacea this is really a venous sinus. 

 PERISSODACTYLA (Trepicro-tis, uneven; SaK-rv\os, toe), a name applied to those 



Ungulate Mammals which have an odd number of digits, as the Tapir and 



the Horse. 

 PERITONEUM (jcepi, around; Teivw, to stretch), the membrane which covers the 



abdominal walls and the contained viscera. 

 PHALANX (<p<i\ay, a rank or row), one of the small bones which compose the 



digits of the higher Vertebrata, otherwise called Internodii. 

 PHARYNX (<pdpvy), the upper part of the gullet. 



PHARYNGOBRANCHTI (<pdpvy, Ppayx ia > g illri ). the order of Fislies represented by 

 the Amphioxus, in which the perforated pharynx performs the function of 

 gills : otherwise called Leptocardii. 

 PHYLACTOL^MATA fyvXcutrts, fr. (pv\dff<ru, guarded ; \aifj.6s, throat), an order of 



Polyzoa in which the entrance to the gullet is guarded by an epistome. 

 PHYSOPHORIDJE (<f>D(ra, bellows ; <pepw, bear), a family of Hydrozoa. 



