4:56 GASTROPODA. [Pfctinibranchia. 



Animal yellowish-wliite spotted with reddish-brown ; the siphon 

 and posterior part of the foot are marked in the same way ; the re- 

 mainder is milk-white. 



Dentition unknown. 



Type in the British Museum. 



Hob. Cook Strait, in a few fathoms (" Astrolabe ") : Queen 

 Chailotte Sound, near Long Island, in 10 fathoms (" Challenger ") ; 

 Cape Faiewell ; Nelson ; off Great Barrier Island, in 110 fathoms ; 

 near Channel Island, Hauraki Gulf, in 25 fathoms ; Auckland Har- 

 bour, in 5 fathoms (H. S.) ; Cape Maria van Diemen. 



Remark. I have never seen this species in the littoral zone. Reeve 

 gives Tasmania and Sowerby Australia as the habitat of the species, 

 but this is undoubtedly erroneous ; it is no doubt precinctive to New 

 Zealand. 



Fossil in the Pliocene. 



Fam. MARGINELLID^E, Adams. 



Animal having tentacles arising close together, the eyes on the 

 lower portion or near the middle of the tentacles ; mantle with ex- 

 panded side lobes, covering the back of the shell ; siphon elongate, 

 simple at the base ; foot large, truncate in front, produced behind. 

 Operculum usually ncne. Formula of radula 0+1 + 0. 



Shell porcellanous. polished, usually smooth or with longitudinal 

 ribs ; spire short or immersed ; body-whorl ample ; aperture nearly 

 the length of the shell ; the outer lip usually with thickened margin, 

 smooth or dentated within ; the inner lip with several distinct plaits 

 on the columella. 



Fossil from the Eocene. 



KEY TO GENERA. 



A. Shell with 4 columella plaits ; without a basal limb . . MARGINELLA. 



B. Shell with more than 4 columellar plaits ; a basal limb present CRYPTOSPIRA. 



Genus 1. MARGINELLA, Lamarck, 1801. 

 Maryinella, Lam., Syst. A.S.V., 1801, 75, Type : Valuta glabdla, L. 



Animal large, but able to draw back into the shell : foot large, 

 broad and subtruncated in front, obtuse or lightly attenuated behind ; 

 tentacles long, cylindrical, sharply pointed, the eyes on the outer 

 sides at about the lower third, situated on ommatophores, which are 

 united with the tentacles. Tooth of the radula transverse, with a 

 great number of small and sharp denticles. 



Shell mostly small, ovately oblong to subcylindrical, polished, 

 mostly smooth, but sometimes with axial ribs ; spire short and conical ; 

 aperture narrow, elongated, sometimes emarginate at the base : outer 

 lip more or less varicose, its inner margin smooth or denticulate ; 

 columella plicate. 



