86 
PROCEEDINGS OF THE SCIENTIFIC ASSOCIATION. 
YIII. Anseres. 
Anatidm 10 species. Laridae 10 species. 
Colymbidse 3 ,, Pelecanidae 6 ,, 
The new species described by Dr. Leotaud are tlie fol- 
lowing : — 
Tachyphonus albispecularis Dendrocolaptes altirostris 
Cymindis Pucherani Empidonax Cabanisi 
The foregoing list shows us that out of 54 families in- 
cluded in Gray’s arrangement 34 are represented in Trini- 
dad. The 20 unrepresented families are either small or of 
very limited distribution. The missing order Struthiones 
for example, is chiefly confined to Africa and Australia, 
having but two species (Rhea) in South- America. 
My own researches among the terrestrial molluska (on 
which subject I have contributed a paper to your Proceed- 
ings) have shown me some reason to place the boundary 
between the North Brazilian or Guianan and Columbian 
provinces as far north as the northern limit of the tertiary 
formations of the valley plain of the Orinoko. Even the 
Columbian region, thus restricted to the north-western 
part of South- America, has some strong affinities with the 
Brazilian region, as, for instance, in the occurrence of spe- 
cies of Plelcocheilus (R. glaber , P. distortus ). But similar 
species (i. e. P. undulatus , P. auris- Sileni) are also found 
in the lesser Antilles. It must not be overlooked, how- 
ever, that the latter depart from the type of Plekocheilus 
and approach the more typical Bulimi. There is also a spe- 
cies of Simpulopsis , an eminently Brazilian type, in Haiti, 
and another in Porto-Bico. On the other hand, the truly 
Antillian affinities of the Columbian region are marked by 
such shells as Cyclotus stramineus, Cistula Tamsiana , Chron- 
dopoma plicatulum and cumanense and Trochatella semilirata . 
