Types and distribution of the coeloconic sensilla (CoS 1–3): (A) Coeloconic sensillum (marked as a square) was observed on the basiflagellum (f1). (B,C) Coeloconic sensillum (CoS1) and cross-section bellow the cuticular surface with the three dendrites ((1+2)+3)). (D,E) Coeloconic sensillum (CoS2) with two chambers (1, 2) and a cross-section of the wall peg showing three dendrites ((1+2)+3)). (F) Distribution of the coeloconic sensilla (CoS3) on the flagellomere (f1) (oval dotted lines). (G) The wall grooved of the CoS3. (H) The sagittal section of the wall and base of the sensillum (CoS3) showing a porous wall and numerous dendrites. (I) Cross-section at the base of the peg with the microvilli (mr) in the lymph cavity of the tormogen cell and the bundle of dendrites (dn). Abbreviations: ap, aperture of holl; cw, cuticular wall with several pores; dn, dendrites; gr, grooved and porous wall; ods, outer dendritic sheath.