USED IN HX loUOLOGY. 



37 



Deutocerebral segment: =antennal segment; q. v. 



Deutocerebrum: the middle portion of the brain, formed by the ganglion of 

 the 2d primary segment ; also termed antennal or olfactory lobes from the 

 parts it innervates. 



Deutoplasm: the yolk or food plasm of an ovum. 



Deutotergite: the secondary dorsal segment of the abdomen. 



Dextrad: extending or directed toward the right. 



Dextral: to the right of the median line. 



Dextro-caudad: extends obliquely between dextrad and caudad. 



Dextro-cephalad: extends obliquely between dextrad and cephalad. 



Di: as a prefix, = two. 



Diaphanous: semi-transparent; clear. 



Diaphragm: any thin dividing membrane; that thin membrane separating 

 the cavity containing the heart from the rest of the body. 



Diarthrosis: any articulation that permits of motion. 



Diastole: that regular expansion of the heart that draws the blood inward: 

 see systole. 



Dichaetae: a group of brachycerous Diptera with a proboscis consisting of two 

 parts : Muscids, etc. 



Dichoptic: Diptera; eyes separated by front; not contiguous: see holoptic. 



Dichotomous: forked: dividing by pairs. 



Dichromatism: the possession of two color varieties. 



Dictyoptera: an ordinal term applied to the roaches: also more generally. 

 to the Orthoptera. 



Didactyle -us: two-toed: with two tarsi of equal length. 



Didymus: double: geminate. 



Difformis: irregular in form or outline: not comparable: anomalous. 



Diffracted: bending in different directions. 



Diffuse: spreading out; without distinct edge or margin. 



Digestive tract: the alimentary canal as a whole: more specifically that por- 

 tion behind the crop, in which assimilation takes place. 



Digitate: finger-like, or divided into finger-like processes. 



Digitiform: formed, shaped like or having the function of a finger. 



Digitules: appendages on the feet of Coccidcc ; in Lecanium, four knobbed 

 hairs. 



Digitus: the terminal joint of the tarsus, bearing the claws: a small appendage 

 attached to the lacinia of the maxilla ; rarely present and probably tactile. 



Digoneutism: the power to produce two broods in one season. 



Dilatatus: Coleoptera; a margin, when the sharp marginal edge extend- 

 beyond its usual limit : the base when the transverse diameter is much longer 

 at one part. 



Dilated: widened, expanded. 



Dilation: an expansion or widening. 



Dilute: thinned out: applied to color means weak or pale. 



Dilutior: much thinned out or diluted. 



Dimera: forms with two-jointed tarsi: specifically applied to some groups of 

 Homoptera. 



