DENTICULATED. Set with small teeth. 

 DENTOID. Having the form of teeth. 

 DENUDED. Divested of covering ; laid 



bare. 



DEPRESSED. Pressed down or flatted hori- 

 zontally ; low, shallow, flat. 

 DEPLUMED. Stripped of feathers or plumes. 

 DERMAL. Belonging to the skin. 

 DESICCATIVE. Having a tendency to ex- 

 haust moisture. 

 DETERSIVE. Having power to cleanse from 



oifensive matter. 



DEXTRAL. Right-handed. Spiral shells are 



said to be dextral when the aperture faces 



the right hand of the observer, the shell 



being held with the apex upwards. 



DIAMETER. The thickness of a body, known 



by a right line passing through its centre. 



DIAPHONOUS. Clear and transparent. 



DIAPHRAGM. A muscular membrane placed 



transversely across the trunk of the human 



body, at about its middle portion, dividing 



it into two pretty nearly equal halves : it 



is one of the chief organs of respiration ; 



its chief function consisting in alternately 



increasing and diminishing the capacity 



of the thorax and abdomen. This term is 



also applied to the septa, by which the 



chambers of multilocular and other shells 



are divided from each other. 



DICEEOUS. A term for any insect that has 



two antennae. 



DICHOTOMOUS. Dividing regularly in pairs. 

 DIDACTYLOUS. Having two toes. 

 DIDYMOUS. When areolets are nearly di- 

 vided into two by a nervure. 

 DIFFUSED. Dispersed, or extended in all 



directions. 

 DIGITATED. Branched out into long points, 



or having finger-shaped processes. 

 DIGITIGRADE. Walking on the tips of the 



toes. 



DILATABILITY. The quality of admitting 

 expansion by the elastic force of the body 

 itself, or of another elastic substance acting 

 upon it. 



DILATATE. Disproportionably broad in part. 

 DILATATION. A spreading or extending in 



all directions. 



DILUVIAL. Effected or produced by a deluge, 

 more especially applied to the general de- 

 luge in the days of Noah. 

 DILUVIUM. A deposit of superficial loam, 



sand, gravel, &c. caused by the deluge. 

 DIMEROUS. When the trunk of an insect 



consists of two greater segments. 

 DIMIDIATE. When the base-covers are about 



half the length of the abdomen. 

 DIMIDIATED. Divided into two equal parts. 

 DIMYARY. A bivalve whose shell is closed 



by two muscles. 



DIOPTRIC. DIOPTRICAL. Relating to that 

 part of optics which treats of the refrac- 

 tions of light passing through different 

 mediums, as through air, water, or glass. 

 DIPTEROUS. Having two wings only. Per- 

 taining to the Diptera, or those insects 

 which have two wings. 

 Disc. The middle of a surface. The middle 

 art of the valves of a shell, or that which 



between the umbo and the margin. 

 DISCOID : DISCOIDAL. Disc-shaped ; much 

 flattened. A spiral shell is said to be dis- 



pnr 



lies 



coidal, when the whorls are so horizontally 

 convolute as to form a flattened spire. 



DISCOLORATE. Of a different colour from 

 the other part. When the upper and under 

 sides of Lepidoptera are of a different 

 colour. 



DISCONTINUOUS. Where parts which are 

 usually connected are suddenly inter- 

 rupted. 



DISCUBITORY. Inclining sideways ; fitted 

 to a leaning posture. 



DISCURSIVE. Moving or roving about. 



DISGORGE. To eject or discharge from the 

 stomach, throat, or mouth. 



DISHEVELLED. Spread out loosely and in 

 disorder. 



DISHORNED. Stripped of horns. 



DISINFECTED. Cleansed from infection. 



DISINTEGRATED. Separated into integrant 

 parts without chemical action. 



DISJUNCT. When the head, trunk, and ab- 

 domen of an insect are separated by a deep 

 incisure. 



DISLOCATE. To put out of joint. In geo- 

 logy, the displacement of parts of rocks, 

 or portions of strata, from the situations 

 which they originally occupied. 



DISMEMBERMENT. The act of severing a 

 limb or limbs from the body ; separation 

 of the members ; mutilation. 



DISORGANIZE. To break or destroy organic 

 structure. 



DISPLUMED. Stripped or deprived of plumea 

 or feathers. 



DISTICHOUS. When the joints of the an- 

 tennae generally terminate in a fork. 



DISTINCT. When spots, &c. do not touch or 

 run into each other, but are completely 

 separate. 



DIVARICATE. DIVARICATED. Standing out 

 very wide ; spreading out widely. When 

 wings of insects at rest are somewhat 

 erect but diverge from each other. 



DIVARICATION. A crossing or intersection 

 of fibres at different angles. 



DIVERGING. Tending to different parts from 

 one point. 



DOE. The female of the fallow deer. 



DORMANT. Sleeping ; in a state of rest and 

 inaction. 



DORSAL. Pertaining to the back ; adhering 

 to the back ; as the dorsal fin of a fish. A 

 dorsal shell is one placed on the back of 

 the animal. The dorsal part of a bi- 

 valve shell is that on which the hinge is 

 placed ; the opposite margins are termed 

 ventral : the dorsal surface of a spiral 

 univalve is that which is seen when the 

 aperture is turned from the observer. 



Do RSI BRANCHIATE. Having gills attached 

 to the back, as in mollusca belonging to 

 the Dorsibrcmchiata. 



DORSO-INTESTINAL. A part which is on 

 the dorsal aspect of the intestines. 



DORSUM. In conchology, the back or upper 

 outward surface of the body of the shell, 

 when laid upon the aperture or opening. 



DOVE-COT. A small building or box. in 

 hich domestic pigeons breed. 



DRAKE. The male of the duck kind. 



DREDGE. A drag-net for taking oysters and 

 other mollusca. 



DREDGING-MACHINE. An engine used to 



