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ON ZGEAN INVERTEBRATA. 131 
to regulate their distribution, and to show the bearings of the investigation 
on the science of geology. 
I shall commence with an enumeration of the species of Mollusca and. 
Radiata, prefacing the tabular view of each tribe with a few general remarks. 
Mo.ttusca. 
Cephalopoda. 
Octopus vulgaris and macropodius, Sepia officinalis and Sepiola rondeletii, 
were the cuttle-fishes which I met with in the eastern Mediterranean. They 
are all inhabitants of the shallows, and are found in or near the littoral zone, 
where they are much sought after by the Greeks as articles of food. They 
are speared at night by torchlight when on their foraging excursions. The 
sandy shores of the island are thickly covered with the shell of the Sepia, 
sometimes forming beds of considerable thickness. In no instance did the 
shell occur when dredging, so that we may suppose that species to be con- 
fined to the littoral zone. The Sepiola rondeletii was taken on the coast of 
Asia Minor, as deep as 29 fathoms in a bottom of weed. Octopus macro- 
podius only occurred once, and then among the rocks near watermark, in the 
Island of Cerigo, at the entrance of the Agean. The Argonauta was much 
sought after, but never found. It is, however, a recorded inhabitant of the 
shores of Greece. 
Pieropoda. 
Eight species of Pteropoda, members of the genera Hyalea, Cleodora and 
Criseis, inhabit the AXgean, and appear to be equally diffused in all parts of 
the eastern Mediterranean. The white mud which forms the sea bottom 
between 100 and 200 fathoms abounds with their remains, many hundreds 
coming up in a single dredge, chiefly Criseis and Cleodora. In the muddy 
deposits of upper regions they are scarce, in those of shallow water altogether 
absent. Though immense numbers of their dead shells were taken, compa- 
ratively few of these testacea occurred in a living state. Of the eight species 
four were taken alive, three of which were Criseis, and the fourth Hyalea 
tridentata. The last was only observed once in the Bay of Cervi, at the en- 
trance of the AXgean, in August 1841: the Crisets were abundant in the 
spring of the same year. They usually abound about three hours after noon 
and towards nightfall, sparkling in the water like needles of glass. Through- 
out the summer and autumn they were very seldom met with. It would 
appear that great flocks of Pteropoda live in the deeper parts of the sea, 
ascending to the surface only occasionally, and at definite seasons. That 
their range in depth is limited, is evident from the fact that their remains 
abound only between 100 and 200 fathoms, diminishing above and below that 
region. 
Nucleobranchiata. 
Seven species of undoubted Nucleobranchiata, with three probable mem- 
bers of that order, inhabit the Zgean, representatives of genera, four of 
which are shell-bearing and two naked. _The observations regarding habitat 
and time of appearance apply equally to the members of this order and those 
of the last, with the exception of the Jirole, which may be seen during most 
months of the year. Of the testaceous nucleobranes, the Atlanta peronii 
and two species of Zadas appear to be universally diffused in the Agean. 
Carinaria is very rare, having only occurred twice, and then dead. A little 
shell of Bellerophon-like appearance is abundant in the mud of great depths, 
and from its resemblance to the young state of Carinaria | have placed it 
here. Two species of that very anomalous genus Sagitéa were met with 
K 2 
