546 A. E. VerriU — Nudihranchs and naked 



Length in life, 12 inches; height, with folded side-lobes, 5.5 inches; 

 breadth across expanded side-lobes, or fins, 10 inches ; length of 

 latter, 7 inches ; breadth of neck, at origin of side-lobes, 3 inches. 



Bailey Bay, on reefs. It swims readily and strongly. 



This species is larger and stouter than the common A. dactylomela^ 

 with much broader side-flaps, or fins. The latter species, in life, is 

 usually lighter yellowish olive or greenish yellow, with ill-defined 

 whitish spots and reticulated with narrow brown or black lines; and 

 on the sides it has also rather large, roundish, ocellated spots of 

 purplish brown, 6 to 12™™ across, with pale yellow or white centers, 

 the dark linear reticulations usually crossing the spots; the inner sur- 

 face of the side-flaps is greenish with about 6 or 7 large, irregular, 

 often rather rectangular, transverse blotches or interrupted bars of 

 dark chocolate-brown or black. 



According to strict rules of priority this should doubtless be called 

 Tethys megaptera, for Mr. Pilsbry has shown that Tethys was orig- 

 inally applied to the genus usually called Aplysia, 



Aplysia (or Tethys) Willcoxi Heilprin (?). 



Aplysia Willcoxi Heilprin, Proc. Acad. Nat. Sci., Philad., p. 364, 1886. 

 Tethys Willcoxi Pilsbry, Man. Conch., xvi, p. 80, pi. 35, figs. 30, 31, 32, 1896. 



Plate LXVI. Figure 1. 



A single specimen of a m^uch smaller and plainer colored species 

 was obtained, which I refer with some doubt to this Florida species. 



The body is relatively longer and less robust than in either of the 

 other species, and the foot extends considerably beyond the posterior 

 end of the side-flaps. The latter ai'e well rounded, moderately lai'ge, 

 and nearly disunited posteriorly. The anal siphon is large and pro- 

 jects far beyond the side-flaps. Mantle-pore simple, subcentral. 

 Oral tentacles large and very wide. 



Colors were not noted in life, but only after being in formalin a 

 short time, when they had probably changed very little. Sides and 

 upper surface of neck, head, foot, tentacles, and outer surface of 

 side-flaps, dull grayish brown, very irregularly blotched, mottled, 

 and streaked with brownish black; top of head mostly black. Inner 

 surface of side-flaps paler gray, with only a few irregular blotches 

 of brown; gill dark brown. 



Length, 6 inches (150"""); length of side-flaps, 3.5 inches; breadth 

 across latter, when expanded, 4 inches. 



Bailey Bay, in shallow water. One example. 



