Structure of the H. dujardini head . All images are of ventral-mounted specimens. Scale bar equals 25 μm. (A) Maximum projection of confocal Z-series. (B-D). Increasingly deeper slices of a DAPI-stained specimen. (B) The ventral lobe appears continuous across the midline. Note the groove that runs through the outer (arrows) brain lobes. (C) The ventral lobe extends on both sides of the buccal tube, suggesting that it is horseshoe shaped. (D) Few cell bodies surround the buccal tube in the interior of the head. (E) Dorsal brain. Abbreviations: ac, anterior cluster; bd, neurite bundles; bu, buccal tube; dc, dorsal cluster; dco, dorsal commissure; ga, ganglion; ic, inner connective ico, inner commissure; il, inner brain lobe; le, leg; ne, neurites of the mouth; oc, outer connective; ol, outer brain lobe; ph, pharyngeal bulb; pn, posterior nerves; vl, ventral brain lobe.