4314 THE ZooLoGisT—FEBRUARY, 1875, 
overlapping bands of the British and Mediterranean faunas. At 
Tenby and on parts of the Devonshire coast are many species of 
sponges not found further north, but common in the Gouliot Caves 
and elsewhere in these islands. A similar overlapping takes place 
in a broad belt extending from about Scarborough to the Scottish 
border on the east, and from the coast opposite Scarborough to the 
Hebrides on the west. Here also there is a mixture of the sponges 
that belong to the northern, with those of the southern, seas, while 
on either side occur species that do not cross the line.” 
Dr. Bowerbank was so very kind as to examine microscopically 
and identify my collection of sponges obtained in the caves. He 
gives the following as the species, viz.:— 
Halichondria panicea, Isodictya pallida, 
Hymeniacidon lactea, Grantia compressa, 
3 caruncula, »  Ciliata, 
a sanguinea, Leuconia nivea, 
Isodictya elegans, Leucosolenia coriacea, 
ix  CACHLL Leucogypsia Gossei, 
and states, “ This is a capital list for one locality.” He further 
says :— Grantia tesselata, Leucosolenia cortorta and Tethea Col- 
lingsii also occur there, but you do not appear to have seen them.” 
I was, however, fortunate in taking one species, the third on the 
list, which appears to be new to the locality, respecting which 
Dr. Bowerbank writes :—“ I have never known Hymeniacidon san- 
guinea so far south as your specimen.” This is an additional 
instance of the “overlapping” before referred to. The colours 
of the species have a most beautiful effect in the caves; they 
range from white to cream-colour, from fawn-yellow to orange, 
various shades of green, and deep blood-red. The crumb-of- 
bread sponge (Halichondria panicea), with its curious volcano- 
like cones, and the striking Hymeniacidon sanguinea of deep 
blood-red colour, vie with each other for possession of space on 
some parts of the rock, and in some instances encrust each other; 
but, as Dr. Johnston (‘ British Sponges, p. 11; Edinburgh, 1842), 
who first noticed the phenomenon, observed, “grew intermingled in 
such a manner that they had formed a specimen resembling the map 
of a county, where every riding was coloured white or red, and 
where the boundaries were too distinctly drawn to admit of any 
debateable acres on either side.” 
The wealth of the lower cave in actinoid life is enormous—such 
as I have never before witnessed on the richest parts of our 
