60 DR. W. BAIRD ON PROTOMA KNOCKERI. [Jan. 27, 
As yet, we have only one species; and I propose naming it after 
its discoverer. It may be thus defined :— 
PROTOMA KNOCKERI. 
Testa elongato-subulata, transversim dense sulcata, sulcis minutis; 
anfractibus sedecem, planulatis, suturis distinctis; apertura 
ovalis, labro infra aperturam acute inciso; operculum circu- 
lare, parvum, multispirale, corneum. 
Long. 23 poll. 
Hab. Whydah, west coast of Africa (Capt. H. H. Knocker, R.N.). 
This species resembles in some respects, generically, the Proto 
cathedralis of Defrance. It is much smaller than that shell, how- 
ever; the sulci or ridges are much finer and more numerous; and 
there are no large circular ribs or sulci at the base of the last whorl. 
Instead of merely an emargination on the under lip, this part of the 
shell is more sharply cut or incised, and the slit is more profound. 
The operculum, which fortunately exists in one specimen, is small, 
circular, and resembles that of Mesalia or Turritella. It is difficult 
to say what the colour is, as in the largest specimen we possess the 
shell is brown, while in all the others it is quite white or colourless. 
Remarks on the Genus Proto of Defrance. 
Taking the Turritella cathedralis of Brongniart to be the type, 
as Deshayes (in the last edition of Lamarck’s ‘ An. sans Verteb.’) 
asserts it to be, of the genus Proto of Defrance, I was at first induced 
to consider the shell just described a species of that genus. A 
further examination, however, has decided me to alter my opinion, as 
the following observations will show. 
In 1815, in the eleventh volume of the ‘ Linnean Transactions,’ 
Leach established the genus Proto for a particular species of amphi- 
podous Crustacea. This name has since then been adopted by 
Desmarest (in 1825), Johnston, A. White (in his ‘ Catalogue of the 
Crustacea in the British Museum’), and by Spence Bate (in his 
‘ Catalogue of the Amphipoda in the British Museum’). 
In the same year (1815) the name of Proto was given by Oken, 
in his ‘ Lehrbuch,’ to a genus of Annelidan worms belonging to the 
Naiadina. This ‘genus was subsequently adopted by CErsted in 
Kroyer’s ‘ Tidsskrift’ in 1843, and by Johnston in his ‘ Catalogue of 
the Non-parasitical Worms in the British Museum.’ Grube, however, 
considers the genus Proto to be synonymous with another genus esta- 
blished by Oken in the same work, and called by him Dero. If this 
synonymy be correct and the genus Dero be adopted, we shall then 
have no difficulty in giving precedence to the genus formed by Leach. 
To render the word Proto, however, still more perplexing, Defrance 
gave the same name to a genus of shells. Inthe ‘ Dict. des Sc. Nat. 
vol. xliii. (published in 1825), this author defined his genus; and 
about the same time it made its appearance in De Blainville’s ‘ Ma- 
nuel de Malacologie.’ As the species upon which Defrance founded 
his genus was figured by him (and reproduced by Blainville in the 
