580 GLOSSARY. 



CTENOPHORA (Gr. kteis, a comb ; andphero, I carry). An order of Actinozoa, 



comprising oceanic creatures, which swim by means of " ctenophores," or 



bands of cilia arranged in comb-like plates. 

 CURSORES (Lat. curro, I run). An order of Aves, comprising birds destitute 



of the power of flight, but formed for running vigorously (e.y., the Ostrich 



and Emeu). 



CUSPIDATE. Furnished with small pointed eminences or " cusps." 

 CUTICLE (Lat. cuticula, dim. of cutis, skin). The pellicle which forms the 



outer layer of the body amongst the Infusoria. The outer layer of the 



integument generally. 

 CUTIS (Lat. skin). The inferior vascular layer of the integument, often called 



the cutis vera, the corium, or the derma. 

 CYCLOID (Gr. kuklos, a circle ; eidos, form). Applied to those scales of fishes 



which have a regularly circular or elliptical outline with an even margin. 

 CYCLOSTOMI. Sometimes used to designate the Hag-fishes and Lampreys, 



forming the order Marsipobranchii. 

 CYST (Gr. kustu, a bladder or bag). A sac or vesicle. 



CYSTICA. The embryonic forms (scolices) of certain intestinal worms (tape- 

 worms), which were described as a distinct order, until their true nature 



was discovered. 

 CYSTOTDEA (Gr. kusiis, a bladder ; and eidos, form). An extinct order of 



JEckinodermata. 



DECAPODA (Gr. deka, ten ; poda, feet). The division of Crustacea which have 



ten ambulatory feet ; also the family of Cuttle-fishes, in which there are 



ten arms or cephalic processes. 

 DECIDUOUS (Lat. decido, I fall off). Applied to parts which fall off or are 



shed during the life of the animal. 

 DECOLLATED (Lat. decollo, I behead). Applied to univalve shells, the apex of 



which falls off in the course of growth. 

 DEINOSATTRIA (Gr. deinos, terrible; saura, lizard). An extinct order of 



Eeptiles. 

 DENDRIFORM, DENDRITIC, DENDROID (Gr. dendron, a tree). Branched like a 



tree, arborescent. 

 DENTIROSTRES (Lat. dens, a tooth ; rostrum, a beak). The group of Perching 



Birds in which the upper mandible of the beak has its lower margin toothed. 

 DERMA (See " Cutis "). 



DERMAL (Gr. derma, skin). Belonging to the integument. 

 DERMOSCLERITES (Gr. derma, skin ; skleros, hard). Masses of spicules which 



occur in the tissues of some of the Alcyonidce (Actinozoa). 

 DESMIDIJB. Minute fresh-water plants, of a green colour, without a siliceous 



epidermis. 

 DEUTEROZOO'IDS (Gr. deuteros, second ; zoon, animal ; eidos, form). The zooids 



which are produced by gemmation from zooids. 



DEXTRAL (Lat. dextra, the right hand). Right-handed ; applied to the direc- 

 tion of the spiral in the greater number of univalve shells. 

 DIAPHRAGM (Gr. diaphragma, a partition). The " midriff," or the muscle 



which in Mammalia forms a partition between the cavities of the thorax 



and abdomen. 

 DIASTEMA (Gr. dia, apart; histemi, to place). A gap or interval, especially 



between teeth. 



DIASTOLE (Gr. diastello, I separate or expand). The expansion of a contrac- 

 tile cavity such as the heart, which follows its contraction or "systole." 

 DiATOMACE^E (Gr. diatemno, I sever). An order of minute plants, which are 



provided with siliceous envelopes. 

 DIBRANCHIATA (Gr. dis, twice ; bragchia, gill). The order of Cephalopoda 



(comprising the Cuttle-fishes, &c.) in which only two gills are present. 

 DICYNODONTIA (Gr. dis, twice ; kuon, dog ; odous, tooth). An extinct order 



of Reptiles. 

 DIDELPHIA (Gr. dis, twice; delphus, womb). The subdivision of Mammals 



comprising the Marsupials. 



