REPORT OjST THE PTEROPODA. 
69 
Station 24, March 25, 1873 ; off Culebra Island; lat. 18° 38' 30" N., long. 65° 5' 30" 
W.; depth, 390 fathoms; bottom, Pteropod ooze. 
Station 33, April 4, 1873 ; off Bermuda; lat. 32° 21' 30" N., long. 64° 35' 55" W.; 
depth, 435 fathoms ; bottom, coral mud. 
Station 78, July 10, 1873 ; off the Azores; lat. 37° 26' N., long. 25° 13' W.; depth, 
1000 fathoms ; bottom, volcanic mud. 
Station 85, July 19, 1873 ; off Palma Island (Canaries) ; lat. 28° 42' N., long. 18° 6' 
W.; depth, 1125 fathoms; bottom, volcanic mud. 
Station 120, September 9, 1873 ; off the coast of South America, between Pernam- 
buco and Bahia ; lat. 8" 37' S., long. 34° 28' W.; depth, 675 fathoms ; bottom, red mud. 
Station 122, September 10, 1873 ; off the coast of South America, between Pernam- 
buco and Bahia; lat. 9° 5' S., loug. 34° 50' W.; depth, 350 fathoms; bottom, red 
mud. 
Station 185, August 31, 1874; off Raine Island ; lat. 11° 35' 25" S., long. 144' 2' 0" 
E.; depth, 135 fathoms; bottom, coral sand. 
Station 335, March 16, 1876 ; Tristan da Cunha to Ascension Island ; lat. 32° 24' S., 
long. 13° 5' AV.; depth 1425 fathoms; bottom, Pteropod ooze. 
Gavolinia / Abildgaard. 
1791. Carolina, Abildgaard, Om Cavolina natans, Anomia tridentata Forskalsei, Skriv. Naturkist. 
Selsk., Bd. i. Heft. ii. p. 173 ( non Bruguiere, 1792). 
1797. Hheda, Humphreys, Museum Calonnianum. 
1801. Hyalxa, Lamarck, System e des animaux sans vertebres, p. 139. 
1810. Archonta, Montfort, Conchyliologie syt4matique, t. it p. 50. 
1815. Trida, Oken, Lehrbuch der Zoologie, t. i. p. 327 (err. hyp. 273). 
1825. Pleuropus, Eschscholtz, Bericht iiber die Zoologische Ausbeute wahrend der Reise von 
Cronstadt bis St. Peter und Paul, Oken, Isis, 1825, Bd. i. p. 735. 
1842. Diacria, Gray, Synopsis of the Contents of the British Museum. 
1859. Orbignyia, A. Adams, On synonyms and habitats of Cavolinia, Diacria, and Pleuropus, 
Ann. and Mag. Hat. Hist., ser. 3, vol. iii. p. 45. 
Characters and Description. — -The shell, which is generally of a horny brown 
colour, is especially characterised (in the adult state, of course) by its much-contracted 
aperture, which is, however, very broad transversely. The lateral portions of this 
aperture, which are narrower than the middle part, are almost separated from it by a 
more or less developed tooth rising from the ventral lip and fitting into a dorsal 
depression. The dorsal lip, which is longer than the ventral, is always more or less 
ventrally recurved ; the ventral lip, much recurved dorsally, is constricted a little in 
front of the aperture, and then reflected ventrally. The ventral surface is always 
bulging. The special form of Cavolinia depends on the fact that the sides of the shell 
1 Named after Cavolini or Caulini. 
