Tethys pilsbryi Letson, 1898

Cunha, Carlo M. & Rosenberg, Gary, 2019, Type specimens of Aplysiida (Gastropoda, Heterobranchia) in the Academy of Natural Sciences of Philadelphia, with taxonomic remarks, Zoosystematics and Evolution 95 (2), pp. 361-372 : 361

Tethys pilsbryi Letson, 1898 Figure 4 F–H

Tethys pilsbryi Letson, 1898: 193, pl. 8, figs 1-4.

Type locality.

Silam, north coast of Yucatan, Mexico.

Type material.

Syntypes, ANSP A7036, 2 specimens (one 97 mm long preserved with shell and other 94 mm long preserved with shell removed, both dissected and radula removed) + 1 slide with radulae and jaw mounted (Heilprin Expedition, 1890) [one specimen ( Letson 1898: figs 2-3), whole, lacking the left rhinophore (added in the figure), dissected ventrally, shell and radula not removed; other specimen, shell and radula removed].

Remarks.

Eales (1960) synonymized this species with A. cervina Dall & Simpson, 1901 because of general morphological similarity, but it differs in having an upturned edge to the rim of the mantle where the purple gland lies (Fig. 4H: ed). This remarkable characteristic is unique in the genus Aplysia . Letson (1898) also described the presence of "a few inconspicuous scattered warts" on the integument, not reported by Eales (1960). However, both features were confirmed in juvenile specimens from Yucatan (ANSP A1993, 10 specimens measuring 25-50 mm). Additionally, A. pilsbryi has a shorter shell (ca 1.2 times long as wide), while the shell of A. cervina is more elongated (ca 1.6 times long as wide) ( MacFarland 1909).

Current systematic position.

Aplysia pilsbryi (Letson, 1898). Kobelt (1897: 240) introduced the combination to the genus Aplysia .