Cerebratulus sp. 1 (Figure 2 [5a–5b]) Material examined. One specimen (176 mm), MZUSP 0 0 0 16, Brazil, Ceará, Paracuru, Praia Pedra da Rachada, 3°23.95' S 39°0.85' W, under rock, on sand, coll. Cecili Mendes, 31.I.2014. Two specimens (27 mm, 52 mm), MZUSP 0 0 0 17, Brazil, Ceará, Paracuru, Praia da Pedra Rachada, 3°23.95' S 39°0.85' W, under rock, on sand, coll. Cecili Mendes, 11.VIII.2014. Field diagnosis. Bright orange anterior third of body; remaining body yellow. Body long and flat, ending in long transparent caudal cirrus. Head triangular shape with red cerebral ganglia visible. Shallow constriction at posterior of cephalic slits demarcates head. Mouth small, immediately posterior to cephalic slits. No eye spots. Animals fragment easily during anesthesia process. Ecology. Specimens were found in muddy sand, under rocks in middle intertidal zone. They appear to be solitary. Remarks. We assign this informally to Cerebratulus, on the basis of a relatively pointed head, a stout foregut region followed by a conspicuously flattened intestinal region and presence of a caudal cirrus. This species differs from C. ignea by the ground color (C. ignea is totally orange, while Cerebratulus sp. 1 is orange on the anteriorly and yellow on the mid-gut portion);by size (C. ignea ranges from 10 to 25mm, while Cerebratulus sp. 1 is 27 to 176 mm); by the shape of posterior end (C. ignea has a wide caudal end, while Cerebratulus sp. 1 has a sharp end); and by the habitat (C. ignea was found inside filamentous algal mat, while Cerebratulus sp. 1 was found in muddy sand).

Published as part of Mendes, Cecili B., Matthews-Cascon, Helena & Norenburg, Jon L., 2016, New records of ribbon worms (Nemertea) from Ceará, Northeast Brazil, pp. 146-156 in Zootaxa 4061 (2) on page 152, DOI: 10.11646/zootaxa.4061.2.4, http://zenodo.org/record/263586