03 6 APPENDIX. 



several times the length of the shell. The tentacles are two, 

 each bearing at the outer side of its base a well-developed eye. 

 There is a lingual ribbon with well-marked rachis and pleurae, 

 and very perfect labial plates with closely-set dental points arm 

 the mouth. Tbe siphon, long and tubular, and formed by a fold 

 of the mantle, protrudes from the shell on the left side. The 

 foot is large and very mobile, the disk broad, and connected by a 

 narrow attachment to the body just beneath the neck ; it carries 

 an operculum behind, and is cleft by a notch in front. The 

 vesicular float, like that of Ianthina, consists of an aggregation 

 of vesicles varying in number and size ; its co-existence with 

 an operculum shows that it is not a modification of the latter. 



A third species of MacgiUivrayia has recently been met with 

 by one of the authors near the Cape de Verd Islands during the 

 voyage of H.M.S. "Actaeon" from England to Rio (the same 

 species as that erroneously referred to at vol. ii. p. 89 as a 

 Calcarella or Brownia), and named by him echinata ; and a 

 fourth species was subsequently taken by him in the South 

 Atlantic, which he described under the name of setigera. 



Vol. ii. p. 89. Genus CALCARELLA. 



D'Orbigny, in Ramon de la Sagra's Work on Cuba, 1841, 

 indicated his HelicophUgma Candei as a new genus under the 

 name of Brownia. In Wiegraann's Archives for 1853 Krohn 

 described a new genus from the coast of Messina, under the 

 name of EcMnospira, which agrees with the Brownia of M. 

 D'Orbigny. More recently M. Souleyet has described the same 

 genus under the name of Calcarella, and Mr. Macdonald under 

 that of Jasonilla. It should therefore have its original name 

 restored as follows. 



Genus BROWNIA, D'Orbigny. 



Animal as in MacgiUivrayia. 



Shell cartilaginous, sub-orbicular, thin, diaphanous, bi-carinate, 

 the keels crenulate, umbilicus perforate ; aperture wide, angular, 

 laterally sinuous. 



