342 FILOGRANA JMPLEXA. 
submarine structures, such as valves of Cyprina Islandica, or to the aperture of Buccinwm 
undatum. Weymouth (Berkeley), forming a thick lining to dead oyster-shells in southern 
waters; in masses attached to the base of Aleyonarian corals. Common on shells dredged 
in 12—20 fathoms off St. Peter Port, Guernsey. The flat surface of such shells as Pinna 
also form a favourite resort for the thin thread-like tubes, which form a network over large 
areas. Forth (Cunningham and Ramage). Clew Bay (Southern). Plymouth (Allen). It 
is cosmopolitan, extending to the Azores (Fauvel, partim). Three hundred fathoms, off 
Norway, Lofoten and Finmark, Sars; Faerde Islands (O. Schmidt); shores of France (De 
Quatrefages, De St. Joseph, Fauvel), Mediterranean (Grube, Verany), Atlantic Coast, 
U.S.A. (Verrill), Gulf St. Vincent, Australia (Fauvel), and extends also to the Red Sea 
(Crossland), Tortugas (Ehlers), Indian Shores (Annandale), and Augener thinks Haswell’s 
Salmacina Australis the same. Gough Island and Antarctic region (Pixell). Vald-stat. 4 
(Ehlers); Northern Seas (Wollebek); shores of Cantabria (Rioja). Marenzeller found 
Salmacina incrustans in deep water in the Adriatic; 390 m., Finmark (Norman); N.H. 
America (Moore). 
The cephalic region presents a smooth gap between the rounded ends of the lamella 
forming a border to the anterior division of the body. A little below the edge of the lamella 
on each side is a flattened process of the collar which expands considerably distally so as 
to form a conspicuous structure. Ventrally the collar in the preparations folds backward 
as a broad lamella split distally mto two lobes, which in all probability are directed forward 
when in the tube. Two eyes occur on the dorsum of the peristomial segment. Hach consists 
of rounded pigmented spherules (‘‘crystallins,” De St. Joseph), numbering in the one 
seven, and in the other eye ten, though these may vary. 
The branchize are eight im number, four on each side, and m the spirit-preparations 
are about half the length of the body. Each consists of a tapered filament with a somewhat 
camerated axis of what De St. Joseph calls mucous cells (giving a transversely barred aspect), 
which have not the differentiation of the Sabellid axis, and become indistinct in mounted 
preparations. The long diameter of these cells is about 33\59 of an inch, their short diameter 
being less. A double row of proportionally thick pinne is attached to the inner edge, each 
pinna having a central axis of similar structure to that of the filament, and the tip is bluntly 
rounded and often curved. ‘The distal pinnee diminish in length, the last being a mere papilla, 
and the filament ends in a short, smooth process often slightly clavate in spirit, and more 
opaque than the rest. Moreover, the dorsal filament on each side terminates in a thin, 
flattened, and somewhat ovoid plate, the pair performing the function of an operculum. In 
others these are absent, and the tips of the filaments are more less modified and enlarged, 
the granular cells in the enlarged tips being arranged in a somewhat regular manner, and 
often hexagonal in outline. In fresh examples the pmne present a double row of rough 
eranular cells (mucous cells, De St. Joseph), set in a hyaline matrix, and in some views 
these have a spiral arrangement. 
In an example a pair of elongated glandular sacs (nephridia ?) occurred in front of the 
sixth bristle-tuft of the anterior region in the coelom, the tips crossing each other (Plate 
CXXII, fig. 1). In structure they were granular. The intestinal canal is dilated behind the 
anterior region (seventh bristle-tuft), and runs as a straight tube from end to end. No 
diatoms or radiolarians were found in it, only brownish granules and sand-particles. The 
