A new species of Pythia Röding, 1798 (Pulmonata, Ellobiidae), from New Ireland, Papua New Guinea

Abstract

Pythia colmani, a new species from the rainforest of New Ireland, Papua New Guinea, is described. The anatomy of the reproductive and nervous systems is studied in detail. The reproductive system agrees with the patterns observed for other species of the genus. The central nervous system, however, presents a slight divergence from patterns previously recognized in the Pythiinae; the right parieto-visceral connective, in the new species, is less than half the length of its left counterpart, whereas in other pythiine species it is slightly longer than half the length of the left parieto-visceral connective. Taking into consideration that the length of the right parieto-visceral connective is nevertheless appreciable, the significance of this deviation from previously recognized diagnostic characters of subfamilial division of the Ellobiidae is minimized . The new species is compared to Pythia scarabaeus (Linnaeus, 1758), P. pyramidata (Reeve, 1842), P. argenvillei Pfeiffer, 1853 and P. savaiensis Mousson, 1869, from which it differs mainly by its more slender, longer shell, by the position of the first outer lip tooth and by the shape of the pseudo-umbilicus.

Key words:

• Ellobiidae
• Pythiinae
• Pythia
• morphology
• anatomy