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 -fa inch. St. Magnus Bay, 30-60 fathoms, 1867. 



Genus SABSIELLA*, n. g. 



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 CytJieridce. 



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 carinae 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 carinse 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 T ^- 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-. 0. 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. 



