GLOSSARY. 83 



Mesophrag'mal (Gr. mesos > middle ; phragma, a partition). 



Applied to the middle apophysis of each endosternite in 



the Crustacea. 

 Mesopo'dium (Gr. mesos, middle ; pous, podos, a foot). The 



middle portion of the foot in the Gasteropoda and Ptero- 



poda. 

 Meso/tery'gial (Gr. mesas, middle; pterux, a wing). The 



middle basal cartilage in the fin of the Elasmobranchii. 

 Mesor'chium (Gr. mesos, middle; orchis, a testicle). A fold of 



the peritoneum developed in connexion with the rudi- 

 mentary testicle in the male foetus. 

 Mesorec'tum (Gr. mesos, middle). A fold of the peritoneum by 



which the rectum is attached to the sacrum. 

 Mesoster'num (Gr. mesos, middle; sternon, the chest). The 



middle portion or body of the sternum. 

 Mesotho'rax (Gr. mesos, middle ; thorax, a breastplate). The 



second somite of the thorax in the Insecta. 

 Mesotro'cha (Gr. mesos, middle; trochos, anything round, a 



hoop). Larvae of the Polychaeta which have the middle of 



the body surrounded by bands of cilia. 

 Mesova'rium (Gr. mesos, middle). A fold of the peritoneum 



developed in connexion with the rudimentary ovary of the 



female foetus. 

 Meta'bola (Gr. metabole, change). A term applied to all those 



insects which undergo metamorphosis. 

 Metabran'chial (Gr. meta, behind; branchia, a gill). Applied 



to that lobe of the carapace in the Brachyura, which covers 



the hinder branchial region of the body. 

 Metacar'pal (Gr. meta, beyond; karpos, the wrist). The 



name given to each bone of the metacarpus. 



Metacar'pus (Gr. meta, beyond; karpos, the wrist). The 



portion of the manus or hand which lies between the wrist 



and the fingers. 

 Metagas'tric (Gr. meta, behind; gaster, the stomach). The 



name applied to those two lobes of the carapace which in 



the Brachyura cover the hinder part of the gastric region 



of the body. 



Metamorpho'sis ) (Gr. transformation). The term applied to 

 Metamor'phosis \ the series of changes which some insects 



undergo, whereby they successively assume three con- 

 ditions, viz., those of larva, pupa, and imago. 

 Metano'tum (Gr. meta, behind ; notos, the back). The tergal 



portion of the metathorax in the Insecta, 

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