Furcal orifice: see sternal into orifice.
Furcate: forked; divided nto two approximately equal divisions.
Furcula: a forked process: an osmaterium {Scanner's comment: sic. See comment under "osmaterium".}: in Collembola the spring or saltatory appendage borne by the fourth abdominal segment: in Orthoptera, a pair of backwardly directed appendages which overlie in a more or less forked position the base of the supra-anal plate.
Furred: covered with dense hair resembling fur.
Fuscescent: becoming brown; with a brown shading.
Fusco-ferruginous: brownish rust red.
Fuseo-piceous: pitch black with a brown tinge or admixture.
Fuseo-rufous: red-brown, approaching liver brown.
Fuseo-testaceous: dull reddish brown [brown ocher].
Fuscous -us: dark brown, approaching black; a plain mixture of black and red [crimson lake + black].