Gen. 48. P lacobranchus, Van Hasselt. Tentacles 4, back with 2 lateral
membranous expansions, having their upper surface covered
with folds. Tongue ? . P.
Gen. 49. Acteonia, Quatref. Tentacles 2 flattened lobes at the sides of
the head, produced behind into points; sides of the back with a
tubercular ridge in the region of the anus. Tongue, a single
plate ivith a large broad spine, A spinous buccal collar . A.
Gen. 50. Limapontia, Johns. Tentacles wanting; sides of the head arched
and carinated; back plain, without appendages. Tongue, a
single plate ivith a large broad spine. A spinous buccal collar L.
Tribe 2. Body cylindrical or compressed.
Fam. 15. PhyllirrAoidte.
Gen. 51. P hyllirrhoe, Per on. Tentacles 2, long; tail truncated. Tongue,
a single central plate ivith numerous denticles . P.
TPYE.
ocellatus, Rang.
senestra, Quatref.
nigra, Johns.
Bucephala, Reran.
LIST OF WORKS AND PAPERS REFERRED TO IN THIS MONOGRAPH.
Alder, J. ' Observations on the Genus Polycera of Cuvier, with Descriptions of two New British Species ;’ • Annals
and Magazine of Natural History,’ V 6, p 387; London, January, 1841.
< Note on Eupfocai»««, Triopa, and Idalia;' -Annals and Magazine of Natural History,’ v. 15, p. 262 ;
April, 1845.
‘Catalogue of the Mollusca of Northumberland and Durham;’ ‘Transactions of the Tyneside Naturalists’
Field Club,’ v. 1, p. 97 ; Newcastle-upon-Tyne, 1848.
Alder, J., and Hancock, A. ‘Descriptions of some New Species of Nudibrancous Mollusca frpm the Coast of
Northumberland;’ ‘Ann. and Mag. Nat. Hist.,’ v. 9, p. 31 ; March, 1842.
‘ Notice of a British Species of Calliopoea, D’Orbigny, and of four New Species of Eolis, with Observations
on the Development and Structure of the Nudibranchiate Mollusca ;’ ‘Ann. and Mag. Nat.
Hist.,’ v. .12, p. 233 ; October, 1843.
‘Description of a New Genus of Nudibranchiate Mollusca, with some New Species of Eolis;* ‘ Ann.
and Mag. Nat. Hist.,’ v. 13, pp. 161 and 407 ; March, 1844. ‘Ann. des Sciences Naturelles,’ 3me
ser., v. 1, p. 190.
‘ Report on the British Nudibranchiate Mollusca ;’ ‘ Report of the British Association for the Advancement
of Science,’ 1844, p. 24.
‘Remarks on the Genus Eolidina of M. de Quatrefages;’ ‘Ann. and Mag. Nat. Hist.,’ v. 14,p. 125 ;
August, 1844.
‘Descriptions of Pterochilus, a New Genus of Nudibranchiate Mollusca, and a New Species of Doris;
‘Ann. and Mag. Nat. Hist.,’ v. 14, p. 329 ; November, 1844.
‘Notice of a New Genus and several New Species of Nudibranchiate Mollusca;’ ‘Ann. and Mag. Nat.
Hist.,’ v. 16, p. 311 ; November, 1845.
* Notices of some New and Rare British Species of Naked Mollusca;’ ‘Ann. and Mag. Nat. Hist., v. 18,
p. 289; November, 1846. }
‘Additions to the British Species of Nudibranchiate. Mollusca;’ ‘Ann. and Mag. Nat. Hist.,’ 2d ser.,
v. 1, p. 189 ; March, 1848.
‘ On a Proposed New Order of Gasteropodous Mollusca ;’ ‘ Ann. and Mag. Nat. Hist.,’ v. 1, p. 401 ;
June, 1848.
•Descriptions of two New Species of Nudibranchiate Mollusca, one of them forming the Type of a New
Genus;’ -Ann. and Mag. Nat. Hist.,’ 2d ser., v. 8, pi 290; October, 1851.
Allman, G. J. ‘On the Anatomy of Actoem, with Remarks on the Order PhUbmttrata of M. de Quatrefages
‘Ann. and Mag. Nat. Hist.,’ v. 16, p. 148; September, 1845.
‘ Note on a New Genus of Nudibranchiate Mollusca ;’ ‘ Ann. and Mag. Nat. Hist.,’ v. 17, p. 1 ; January,
1846.
Baster, J. ‘Opuscula Subseciva;’ Harlemi, 1759—1765.
Bate, C. Spence. ‘Notes on the Fauna of Swansea and the Neighbourhood;’ ‘Report of Swansea Literary and
Scientific Society ;’ Swansea, 1850.
Blainville, H. M. Ddcrotay de. ‘ Manuel de Malacologie et de Conchyliologie ;’ Paris, 1825.
Blanchard, E. ‘Recherches sur l’Organisation des Mollusques Gastéropodes de l’Ordre Opisthobranches
‘Annales des Sciences Naturelles,’ 3me ser., v. 9, p. 172, and v. 11, p. 74 ; Paris, 1835.
Bommé, L. ‘ Bericht vegens een zonderling Zee-Insect, gevonden aan einige zee wieren gevischt op het strand van
het eiland Walcheren ;’ ‘Act. Yless.,’ v. 1, p. 394, v. 3, p. 290, and v. 6, p. 357 ; Flushing.
B ouchard-Chan tereaüx. ‘ Catalogue des Mollusques Marins, observés jusqu’à ce jour à l’etat vivant sur les
Côtes du Boulonnais;’ Boulogne-sur-Mer, 1835.
Cantraine, F. ‘ Malacologie Méditerranéenne et Littorale ;’ Bruxelles, 1840.
Cavolini, F. * Memorie per servire alla Storia dei Polipi Marini ;’ Napoli, 1785.