282 DR. P. L, SCLATER ON THE KNOWN [Mar. 14,. 
typically Muricoid. The essential features are those of MW. dubia; 
the pale colour and delicate sculpture and imbrication may arise 
from a deep-water station, as is seen in similar European shells. 
Mr. Cuming, however, regards it as distinct. 
6. Ox a New Species or tHe Genus BAstLeuTEeRvS OF CABA- 
NIS, WITH A SYNOPSIS OF THE KNOWN SPECIES OF THE 
Genus. By P. L. Scuater, M.A., Pa.D., F.R.S., SECRE- 
TARY TO THE SOCIETY. 
(Plates IX., X.) 
Dr. J. Hartlaub, of Bremen, has most kindly placed at my dis- 
posal a skin of a species of the genus Basileuterus, belonging to the 
family Mniotiltidze, which he has lately received from a collector in 
Demerara. Whilst drawing up the characters of this bird, which 
appears to me to be new to science, I have taken the opportunity of 
giving a list of the known species of this genus, together with such 
short diagnoses as may serve to distinguish the species. 
The genus Basileuterus was first established by Cabanis in 1848 
(Schomburgk’s Reise nach Guiana, iii. p. 666), although it had been 
mentioned by name, without any characters being assigned to it, in 
his well-known “ Ornithologische Notizen,” published in Wiegmann’s 
‘Archiv’ * for the previous year. The type given is the Sylvia ver- 
mivora of Vieillot, founded on Azara’s ‘‘ Contra-maestre coronado,” 
no. 154. The next place where we find the genus mentioned is in 
Bonaparte’s ‘ Conspectus,’ where ten species are assigned to it. 
This part of Bonaparte’s work was, if we are not much mistaken, 
composed at Berlin; and the arrangement followed was probably, 
therefore, taken from the shelves of the Berlin Museum, where the 
specimens had at that time been arranged by Dr. Cabanis according 
to his own views. I believe, therefore, that we shall not be wrong in 
assuming that the list of species given in the ‘ Conspectus’ consists 
nearly of such as its founder would have attributed to the genus. 
In the ‘Museum Heineanum’ Dr. Cabanis gives only two species 
besides the type, namely, B. culicivorus sive brasieri and B. ruber 
(Setophaga rubra, Sw.), which latter is more correctly located in a 
separate section, Cardellina. 
Professor Baird has given a very good arrangement of the Mnio- 
tiltine forms in his ‘Birds of North America’ (p. 234). This ar- 
rangement I have followed very nearly in my ‘ Catalogue of American 
Birds ;’ and I see no reason for departing from it. Professor Baird 
places Basileuterus in the Setophagine division of the Mniotiltide, 
between Cardellina and Setophaga. ‘The only alteration I am dis- 
posed to suggest here is to remove Cardellina, which is decidedly 
an aberrant form leading off towards the Tanagers, to the extremity 
of the group; and to locate Basileuterus between Myiodioctes and 
Setophaga, to both of which it is certainly nearly allied. 
* 1847, pt. 1, p. 316. 
