ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 293 
small nodulous processes, one just opposite the commencement of each 
dorsal slope, anteally scarcely rising at all to join the dorsal slope 
which at that extremity meets the ventral line very much below the 
centre ; posteally sloping upwards obliquely, and meeting the dorsal 
margin at a rounded point a little below the middle of that extremity ; 
surface perfectly smooth and glabrous. Ventral aspect boat-shaped, 
the resemblance most striking, centrally depressed at the juncture of the 
valves ; bows moderately sharp, of good breadth of beam, sculptured 
with raised thread-like concentric lines representing the timbers, while 
the small nodulous processes (mentioned in describing the lateral view) 
will stand for the thole-pins; the dorsal and end views bear out the 
allusion, the former representing a boat viewed from below, with a 
well-marked keel, and the latter being triangular with gently rounded 
sides. Length about 3; inch. St. Magnus Bay, 30-60 fathoms, 1867. 
Genus SARSIELLA*, n. o. 
) 
Carapace subrotund, with a rostrate posterior (?) projection, much com- 
pressed ; surface of valves very rough, with greatly elevated rib-like sculp- 
ture ; ventral margin quite flat in its central portion. 
These are certainly not satisfactory generic characters, being so in- 
complete, but having only one good specimen I am unwilling needlessly to 
run the risk of destroying it in the attempt to separate the valves, and 
therefore am unable to describe the hinge-structure or animal. The cara- 
pace is, however, so remarkable that I cannot place it in any described genus. 
It is the largest of British Cytheride. 
Sarsiella capsula, n. sp. Carapace nearly circular, with a short rostriform 
process running out from the extremity; dorsal and ventral margins 
each nearly semicircular; anterior margin completely and widely 
rounded ; posterior with a rostrate process below the middle, the ven- 
tral margin rather angled in its upward slope, but the dorsal perfectly 
rounded. Surface of valves extraordinarily rugose, with concentric 
greatly elevated carine enclosing a deep hollow in the centre of the 
valves, and on their exterior side having numerous radiating ribs pass- 
ing off in all directions to the margin; interstices of these ribs and 
inner slopes of carinz sculptured with circular pittings. Ventral 
aspect very irregular, in the centre a quadrangular flat portion sculp- 
tured with circular pittings. Anterior portion with tuberculately con- 
vex gradually approximating sides; posterior portion consisting of the 
rostriform process, which is seen projecting beyond the truncate extre- 
mity of the quadrangular portion. End view with flat sides dorsally 
arched, ventrally truncate. The valves are very much compressed, though 
appearing more tumid than they really are, on account of the great 
elevation of the sculptured surface. Length about 7~ inch. St. Mag- 
nus Bay, 30-60 fathoms. 
Cytheropteron latissimum (Norman). St. Magnus Bay, and 10 miles east of 
Balta, 30-73 fathoms. 
nodosum, Brady. In the same localities as the last. 
—— punctatum, Brady. 10 miles east of the Island of Balta, in 73 
fathoms. 
* Named after Herr G. O. Sars. A genus Sarsia is already established in honour of 
the father, Professor Sars. I have given this genus a diminutive termination in reference 
to the son, one of the ablest and most accurate of the younger naturalists of the day, 
whose admirable Monograph on the Scandinavian Marine Ostracoda points to a fitness in 
associating his name with that order, 
