94 LIMACINID^. 



disk; mouth central ; tentacles elongated, connate ; eye-tubercles 

 minute. Larva shell-bearing. 



COROLLA, Dall, 18*71. Like Tiedemannia, but with the body 

 pendant below, unattached to the pinnae, ovoid, constricted 

 above; oesophagus produced, aperture trumpet-shaped, produced 

 into two points ; pinnae forming a single disk with reticulated 

 muscular bands, separated by a deep sinus from the oral portion. 

 No shell. T. sjjectabilis, Dall. N. Pacific Ocean. 



Family LIMACINID^. 



Shell minute, spiral, sinistral, calcareous. Operculum pauci- 

 spiral, vitreous. 



Animal with fins attached to the sides of the mouth, and 

 united ventrallj^ by an operculigerous lobe ; mantle-cavity large, 

 opening dorsally ; excretor}^ orifices on the right side. 



The shells of the true Limacinidse are sinistral, by which they 

 may be known from the fry of Atlanta, Carinaria, and most 

 other gastropods. 



LiMACiNA, Cuvier, 1817 = 



Etyra. — Limacina, snail-like. Syn. — Spiratella, BL, 1824. 



Distr. — 2 sp. Arctic and Antarctic Seas ; gregarious. L. 

 Antarctica^ Forbes (xlii,20\ 



Shell subglobose, sinistrally spiral, umbilicated ; wl^iorls trans- 

 versely striated ; umbilicus margined. 



Animal with expanded fins, notched on their ventral margins. 



Valvatella, Morch, 18t4. 



Syn. — Planorbella, Gabb, 1812 (not Haldeman). 



Distr. — Tertiary ; Sicily, Denmark, West Indies. V. atlanta, 

 Morch. P. imitans^ Gabb. 



Shell minute, vitreous, sinistral, apex sunken as in Planorbis. 

 The type, a West Indian fossil, might be taken for a young- 

 specimen of Planorbis trivolvis were it not sinistral. 



Spirialis, Eydoux and Souleyet, 1840. 



Syn. — Heterofusus, Fleming, 1825. Heliconoides, d'Orb. 

 Peracle, Forbes. Sceea, Ph., 1844. 



Distr. — 12 sp. Greenland and Norway to Cape Horn, Indian 

 Ocean, Pacific. S. ventricosa^'Ey d. (:x\u, 21). Fossil. Eocene; 

 Paris l3asin. Pliocene ; Sicily, Rhodes. 



Shell minute, hyaline, sinisti'ally spiral, globose or turreted, 

 imperforate or narrowly perforated, smoot"h or reticulated; oper- 

 culum thin, glassy, semilunar, slightly spiral, with a central 

 muscular scar. 



Animal with narrow, simple fins, united by a simple, transverse 

 operculigerous lobe ; mouth central, with prominent lips. 



