GLOSSARY. 



ABDOMEN (abdere, to conceal), in Mammalia the part of the trunk below the 



diaphragm ; in Insecta the third coalesced segment of the body of the Imago. 

 ACALEFHJE (a/caA^^T), a nettle), jelly-fish : they formed a class of Cuvier's Kadiata, 



and are now included under Hydrozoa. 



ACANTHOCEPHALA (&Kav0a, & thorn ; KerpaXi], head), a group of Scolecida. 

 ACAKINA (S/capi, a mite Arist. Hist. An. v., xxxii. 2), an order of Arachnida. 

 ACETABCLVM, a vinegar bowl (acetum), applied to the socket of the hip-joint in 



Vertebrata, and to the suckers on the tentacles of Cephalopoda. 

 ACTINOZOA (aKT/s, a ray ; &ov, an animal), a class of Ccelenterata. Cf. Anthozoa. 

 ALISPHENOID (a/a, a wing ; ff^v, wedge ; e'TSos, form ; the lateral part of the second 



cranial segment, the greater wings of the sphenoid bone in Man. 

 ALLANTOIS (aAAas, a sausage), a foetal membrane of Amniotic Vertebrata. 

 AiVEOLrs i^dim. of alvus, belly , a hollow cavity, specially applied to the sockets of 



teeth. 

 AMBULACBUM, a garden walk (ambulare), applied to the perforated spaces which 



run from the apex to the base of a sea-urchin. 

 AMCEBA (o/xo<0^, a change), one of the Protozoa which is continually changing its 



form : hence it was formerly called Proteus. 

 AMPHIBIA (KM^'I both; /3os, life), living on land and water, and so applied by 



Linnaeus to Eeptiles and by others to Seals (Ptnuipedia), but now recognised 



as the title of a class of Vertebrata, Cuvier's Batrachia, which at some time 



or other can breathe either in air or water. 

 AMPHTOXUS (o^<pi, both ; ous, sharp), the generic name of a fish, the only member 



of the order Pharyngobrauchii, which has no enlargement of the brain or 



skull, and therefore tapers nearly equally at each end. 

 AMPHIPODA (dju<f>i, both ; iroi/s, foot), a group of Crustacea in which the feet served 



both for walking and swimming, included under Edriophthalmia. 

 ANALOGY (a.va.\oyia, proportion), the relation between parts which agree in 



function ; as the wing of a bird and a butterfly, the tail of a whale, a fish and 



a sagitta. 



ANKYLOSIS (dyKv\<affis] sometimes written anchylosis in anatomy, the coales- 

 cence of two bones so as to prevent motion between them. 

 ANNELIDA or " Annulata " (annellus, dim. of anulus or annulus, a ring), a class of 



Annulosa. 

 ANNULOSA (annulus, a ring), a primary division of the sub-kingdom, corresponding 



with Cuvier's Articulata. 

 ANOPLOTHERICM (a privative; OTTA.OJ/, a weapon), an extinct genus of mammals 



unprovided with horns. 

 ANTENNA (the yard of a ship), applied to the appendages of one somite of the head 



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