ON SGBAN INVERTEBRATA. 155 
may be regarded as its inferior limit. Its mineral nature is as various as the 
coast-line, and its living productions are influenced accordingly ; sand, roek 
or mud presenting their several associations of species. Limited, too, as is its 
extent, it nevertheless presents well-marked subdivisions. That portion which 
forms the water-mark, and which (though in the Mediterranean the space be 
very small in consequence of the very slight tides) is left exposed to the air 
during the ebb, presents species peculiar to itself. Such on rock are Littorina 
ceerulescens, Patella scutellaris, Kellia rubra, Mytilus minimus, and Fossarus 
adansoni ; on sand, Mesodesma donacilla, a bivalve which buries itself in great 
numbers immediately at the water’s edge ; in mud, a mineral character almost 
always derived from the influence of the influx of fresh water, Nassa muta- 
bile and neritoidea ; Cerithium mammillatum on all bottoms, usually under 
stones or weed; Truncatella truncata and Auricula. All these species are 
gregarious, most of them occurring in considerable numbers, and they are 
almost all Mollusca having a great geographic range ; eight out of the eleven 
being widely distributed in the Atlantic, and one, the Littorina ccrulescens, 
extending from Tristan d’Acuna to the shores of Norway. The fuci of the 
coast-line, such as Dietyota dichotoma and Corallina officinalis, are also spe- 
cies of wide geographic diffusion. The bottomless barnacles ( Ochthosia) are 
characteristic of this belt. 
Immediately below this boundary line between the air and the water, we 
have a host of Mollusca of peculiar forms and often varied colours, associated 
with numerous Radiata and Articulata. In this under-belt we find the most 
characteristic Mediterranean forms, those which exhibit the action of the 
climatal influence most evidently. Boring in the sand live Solen strigit- 
latus, Lucina desmarestii, Amphidesma sicula, Venerupis decussata, and va- 
rious species of Donaa, Tellina and Venus; in the mud abounds Lucina 
lactea; on the rocks we find Cardita calyculata, Arca barbata, Chama gry- 
phoides, Lithodomus, Chiton squamosus and cajetanus, Patella bonnardi, 
Fissurella costaria, several species of Vermetus, Haliotis, numerous and pecu- 
liar Trochi, Cerithium fuscatum, Fasciolaria tarentina, Fusus lignarius, 
Murex trunculus, Pollia maculosa, Columbella rustica, Cyprea spurca, and 
Conus mediterraneus, with various Radiata and Articulata, most of them 
peculiar forms. In this belt, in fact, we have the characteristic species of the 
Mediterranean fauna, those animals which give a subtropical aspect to the 
general assemblage of forms in that sea. It is worthy of note, that not onl 
is the climatal influence evident in the colouring and size of the shells of Mol- 
lusca in this region, but also in that of the animals themselves, which often 
present the most varied combinations of brilliant hues, sources of well-marked 
specific character. This is especially the case with the Gasteropoda, and is 
equally true with the sublittoral forms of the Northern as of the Southern 
seas. 
It is only in this subdivision of the highest zone that we see distinct in- 
stances of local distribution of species in the Egean. This is especially the 
case with the genus Zrochus, some of the species of which have a very limited 
distribution, though always abundant where they occur. It is also the case 
with the naked Mollusca and with Zoophytes. Among the last, the rocks of the 
first zone in Asia Minor are well distinguished from those in the islands, by 
the great abundance of a beautiful coral, Cladocora cespitosa, which is 
found in large masses, but does not appear to live deeper than six or eight 
feet below the surface of the water. In the sheltered gulfs of Lycia and Caria, 
sponges (not the kinds used in commerce) of singular shapes and bright 
colours abound in this region, growing to a considerable size. In the Cy- 
clades the beautiful Actinea rubra abounds in similar localities. Padina 
