GASTROPTERIDAE 2 8 3 



mantle reflexed and closed over the shell, in lacking central teeth in the 

 radula, and in having a much more degenerate shell. 



Genus Philine Ascanius 1772 

 Philine quadrata S. Wood Quadrate Paper-bubble 



Figure 596 



Arctic Seas to North Carolina. 



/4 inch in length, moderately fragile, semi-transparent, white, squarish- 

 oval and more constricted toward the top. Aperture large, flaring, and 

 rounded below. Early whorls very small. Sculpture of numerous spiral 

 rows of microscopic oval punctations. Suture deep. The narrow top of 

 the aperture is slightly higher than the apex. Commonly dredged off the 

 New England states from 20 to 400 fathoms. 



Philifie lima Brown File Paper-bubble 



Figure $^i 



Arctic Seas to Cape Cod, Massachusetts. 



H inch in length, much more oblong than quadrata, with the top of the 

 aperture well below the apex, and sinuate from a top view. Columella fairly 

 strong. Sculpture of spiral rows of scalloped lines forming chains, between 

 which are a single scalloped line. Moderately common in fairly shallow 

 but cold water. Ahas P. lineolata Couthouy. 



Philifie sagra Orbigny Crenulated Paper-bubble 



North Carolina to southeast Florida and the West Indies. 



% to /4 inch in length, oblong, fragile, white, with a large aperture, 

 with numerous spiral lines of small oblong rings placed end to end, and char- 

 acterized by the finely crenulated lip. Top of the aperture the same height 

 as the apex. Not uncommon from 15 fathoms down. 



Family GASTROPTERIDAE 

 Genus Gastropteron Kosse 181 3 



Shell entirely internal and consisting of a minute, nautiloid, calcareous 

 spire. Body sack-shaped, with two large, wing-like, fleshy flaps, one on each 

 side of the body. These peculiar, small sea-slugs swim through the water 

 in a bat-like manner. 



Gastropteron rubrum Rafinesque Bat-wing Sea-slug 



Figure 6oe 



West coast of Florida to the West Indies. Mediterranean. 



