GLOSSARY. 185 



Lobe (p. 28). A rounded projection from the common 

 outline. 



Longitudinal (p. 66). Arranged lengthwise. 



Metamorphosis (p. 41). Such an alteration of form 

 as takes place when a caterpillar becomes in succession 

 a chrysalis and a butterfly. 



Monotrematous (p. 26). Having but one opening to 

 the body, serving both for mouth and vent. 



Natatory (p. 130). Serving for swimming. 



Normal (p. 26). Ordinary ; as it usually appears. 



Operculum (p. 92). Anything that shuts up an 

 opening. 



Oral (p. 50). Belonging to the mouth. 



Orbit (p. 163). The hollow in which the eye is set. 



Ovate (p. 11). Somewhat oval. 



Parasitic (p. 22). Living habitually on other 

 animals. 



Pectinated (p. 99). Set like the teeth of a comb. 



Pelotonnement, par (p. 11). As cotton is rolled on 

 a reel. 



Pinna? (p. 34). Processes set in two rows, like the 

 beards of a feather, or the leaflets of a rose. 



Prehensile (p. 122). Capable of catching hold. 



Radiate (p. 17). Having the organs arranged like 

 the spokes of a wheel, around a centre. 



Reticulated (p. 67). Forming a network. 



Respiratory (p. 81). Formed for breathing. 



Retractile (p. 20). Capable of being withdrawn, 

 like the horns of a snail. 



Sac (p. 48). A bag. 



Sessile (p. 18). Without foot-stalks. 



Siliceous (p. 25). Formed of flint. 



