Referring to the palpi when horizontally projecting in front of the face. In this case, the axis of the palpi is parallel to the axis of the body.
directed forwards and downwards
to stretch forth; to present
• (a.) Extended horizontally; stretched out.
Spreading outward and forwards.
Extending horizontally forward: applied especially to antennae.
Por·rect' adjective [ Latin porrectus , past participle of porrigere to stretch out before one's self, to but forth.] Extended horizontally; stretched out. 
Extending horizontally forward: applied especially to antennae.
directed forwards and downwards
directed outward and forward