EAST COAST MARINE SHELLS 



145 



Family Dorlgitatldae 



GENUS GEITODORIS Bergh 1891 



GEITODORIS COMPLANATA Verrill. Range 85- 

 146 fathoms. 



PI. 66, Fig. 6 



South of Martha's Vineyard 



SUBCLASS PULMONATA 

 (Air Breathers) 



ORDER BASOMMATOPHORA 



Family Ellobiidae (Auriculidae) 



Amphibious mollusks, breathing air 

 but apparently dependent upon plenty of 

 moisture, living close to the sea. Members 

 of certain genera are covered by the tide 

 four hours out of twelve. 



Shell spiral with a horny epider- 

 mis; aperture long, with strong folds on 

 inner lip, outer lip often toothed or 

 grooved inside. 



Animal with respiratory orifice on 

 the right side. 



GENUS AURICULASTRUM Fischer 1883 

 (EAR SHELLS) 



Mantle margin of animal thickened; 

 foot simple. 



AURICULASTRUM PELLUCENS Menke. Transparent 

 Ear Shell. This was collected by Rhoades 

 near Miami, Florida, only in and under the 

 soft rotten mangrove branches which lay on 

 the mud in the mangrove swamps along the 

 bay side. They deeply imbed themselves in 

 the rotten wood. It also has been reported 

 from Sanibel and Highland Point, west Flor- 

 ida. Length 18 mm. 



PI. 55, Fig. g 



Cedar Keys, west Florida to 



Demerara 



GENUS PHYTIA Alexia Gray 1847 



Shell thin, spire pointed; inner 

 wall with one to five teeth, outer lip with 

 teeth or thickening inside. 



PHYTIA MYOSOTIS Drap. Shell semitranspar- 

 ent, smooth, shining; whorls seven to eight; 

 outer lip expanded and thickened, some- 



times with tooth-like folds on inside; sharp 

 white teeth below inner wall and a smaller 

 one above it. Length 8 mm. 



This shell probably was introduced 

 to America from Europe through commerce. 



PI. 55, Fig. 3 



Nova Scotia to West Indies 



GENUS TRALIA Gray 1840 



TRALIA PUSILLA Gmelin. Shell a rich deep 

 chestnut-brown color, often almost black; 

 varying in shape from oval to elongate; one 

 fold upon columella, two upon parietal wall; 

 outer lip thickened, inflected in center 

 with single revolving ridge on its inside. 

 Length 13 mm. 



Collected by Earl Moore at Miami, 

 Florida. 



PI. 55, Fig. 6 

 PI. 67, Fig. 5 



Miami, Florida southward to Guade- 

 loupe, West Indies 



GENUS PEDIPES Scopoli 1777 

 (STEPPING SHELL) 



Foot of animal divided inferiorly 

 by a transverse groove. Shell subrounded, 

 transversely ridged, spire short; inner lip 

 with three plaits, outer lip with two in- 

 ternal teeth, lip margin sharp. 



The generic name was applied on ac- 

 count of the peculiar mode of progression. 

 The animal moves by a series of little 

 steps and the strange movements are execut- 

 ed with such rapidity that Pedipes is one 

 of the most agile of mollusks. 



PEDIPES ELONGATUS Dall . Shell longer and 

 more pointed than the following species; 

 comparatively smooth; suture lightly im- 

 pressed. Length 4 mm. 



PI. 67, Fig. 4 



Marco, west Florida 



PEDIPES MIRABILIS Muhlfeld. Shell small, 

 whorls about four, sometimes shouldered; 

 whorls lirate spirally; outer lip sometimes 

 callous and with low teeth inside, both 

 sometimes absent. Length 3 mm. 



This Pedipes enters shallow water 

 near the inside of the North Inlet at Palm 

 Beach, apparently to deposit its eggs in 

 the late spring, later returning to deeper 

 water. It may be observed under stones be- 

 tween tide marks. A variety is shown on 

 PI. 67, 



