GUPPY GULF OF PARI A. 
117 
such localities the line of demarcation between land and water is 
vague and indefinite being formed by tidal (mangrove) s\\ amps. 
In all such parts of the Gulf the fauna is of a peculiar type, quite 
lacking the characteristic forms of truly marine life. The littoral 
niollusks here are the oyster, the periwinkle and the neritine , 
while on the muddy bottom below tidemarks Pyrula melongena, 
Venus pectorina and Mytilus brasiliensis are abundant. heie 
a mud-flat exists to which some degree of firmness is imparted 
hy an. admixture of sand we find numbers of the most delicious 
bivalve in the world, namely Asapkis dejlorata , a largei species 
than its eastern congener and representative As aphis i ugosci. 
On the steeper shores and on those which appioacli the ma 
sea the molluska are more varied and comprize with fev excep- 
tions the forms found throughout the region. Even here, how- 
ever, we trace the influence of surrounding conditions in the c 
of many of the shells. This is of a more lugubrious and uni orm 
hue than in the antillian representatives of the same spe ■ 
particularly striking examples of this I may quote I oluta 
and Fasciolar ia tulipa. Of the former the Ti in id ad I- * 
are very dark and the lines and spots are of an ^ tel b 
instead of the pinkish-brown of antillian specimens. Of the ia 
named shell Trinidad examples are usually of a um onn 
without any lines spots or markings whatever. T ie c ai 
monotonous tints of the molluska of the West Coast o - 
has been made the subject of a paper by Fischer in the Journal^de 
Conehyliologie 1875 (p. 105). The only of coral 
find in common between the two regions is ‘ varied 
I„ „„ «'here cr.l reel. 
•ml brilliant b»e, but Mother it « tb. P*«»“ 
reel, that ou.our to ft. **<* ?£££?* 
are merely concomitant consequence., fact to the effect 
clear. In our case we might have aten >e , ^ w ;u no t 
of the waters of the Orinoco ; hut such an exp 
meet ,h, ca« of the went coaat of South A—, *l“» • 
rivers are absent, 
