Arenopontia? gussoae Cottarelli, 1973a sensu Mielke (1987) [2 nd form]

Original description. Mielke (1987): 330, 334; Abb. 9C.

Body length. Unknown.

Distribution. Northern Chile, (1) Las Lozas beach, a few km south of Coquimbo and (2) Playa Brava in Iquique.

Remarks. In addition to the ”normal form” (here considered as a distinct species, N. chilensis sp. nov. —see above), Mielke (1987) also distinguished a ”2nd form” in his Chilean material that he provisionally identified as Arenopontia? gussoae . According to Mielke (1987), the latter differs from N. chilensis sp. nov. in (1) rostrum somewhat wider, (2) spinular ornamentation of inner spinous process of P5 more pronounced, (3) caudal ramus without medial spur near insertion site of dorsal seta VII, and (4) position of caudal ramus seta III more distal, originating near base of caudal process. Mielke’s (1987) only illustration of the second form depicts the anal somite and caudal ramus in lateral aspect, revealing the elongate, virtually straight, spinous process (50% of caudal ramus length vs 35% and dorsally recurved) and the non-recurved anal processes as additional differences separating it from N. chilensis sp. nov. (Table 4). Although the sympatric occurrence of both ”forms” in the same beach made Mielke (1987) speculate that they may represent different species, he preferred to consider them as morphs of the same species pending the arrival of ecological data. The second form is here treated as distinct from N. chilensis sp. nov. but assigned uncertain status due to the lack of additional morphological information.