390 



MR. G. S. BRADY'S MONOGRAPH OF 



2. Bairdia acanthigera, n. sp. (Plate XXVII. figs. 18-21.) 



Atlantic type. Distribution : Recent — England. 



Valves tumid ; seen from the side subquadrilateral, nearly equal in height throughout ; 

 greatest height in the middle, equal to about half the length. Anterior margin broad, 

 flattened, or obliquely rounded, armed with six to eight short blunt spines or tubercles, 

 which project straight forward. Posterior extremity obliquely rounded towards the 

 dorsum, bearing at the ventral angle about four spines, similar to those on the front 

 of the shell. The dorsal margin forms a flattened arch, and is highest in the middle, 

 sloping rather steeply behind. Ventral margin slightly concave in front of the middle, 

 swelling into a rounded, flattened protuberance in front. Dorsal aspect elliptical, with 

 flattened sides and suddenly tapering extremities ; breadth equal to about half the length ; 

 line of junction of the valves waved. The left valve is the larger, and, in the centre of 

 the ventral surface, considerably overlaps the right. End view somewhat triangular, 

 flexuous, angles rounded. The surface of the shell is closely punctate ; colour dull 

 white. Lucid spots seven or eight, forming a rosette. Animal unknown. 



Length -^^ in., height tq in. : . 



Hab. In deep water. Channel Islands {Mr. Jeffreys' s dredgings) ; Devonshire coast, 60 fathoms {Mr. 

 Spence Bate's dredgings) ; Plymouth, from trawlers {Mr. Barlee) . 



8. Bairdia obtusata, G. O. Sars. (Plate XXXIV. figs. 22-25.) 



Bairdia obtusata, Sars, Oversigt af Norges marine Ostracoder, p. 24. 

 Scandinavian type. Distribution : Recent — Norway, Scotland. 



Carapace moderately compressed; lateral view subrhomboidal, highest near the 

 middle ; greatest height equal to half the length. Anterior extremity obliquely rounded, 

 almost truncate ; posterior obliquely rounded, almost angular below, well rounded above. 

 Dorsal margin evenly arched ; ventral gently sinuated in front, and somewhat convex 

 behind. Seen from above, the outline is elongate oval, the extremities equally and obtusely 

 pointed ; greatest width in the middle, equal to more than one-third of the length. The left 

 valve overlaps distinctly along the whole length of the dorsum, and forms a distinct overlap- 

 ping curvature in the middle of the ventral surface. Hinge-line slightly flexuous. End 

 view broadly oval. Surface smooth, white or fawn-coloured. Animal unknown. 



Length -^5- in., height in. i ^^-O'www 

 Hab. The Minch, 45-60 fathoms {Mr. Jeffreys). 



I have met with only two specimens of this very distinct species, both of them dredged 

 near the Hebrides by J. G. Jefireys, Esq. 



4. Bairdia complanata, Brady. (Plate XXXIV. figs. 1-4.) 

 Bairdia complanata, Brady, Brit. Assoc. Report, 1866, p. 210. 

 Scandinavian type ? Distribution : Recent — Scotland. 



Carapace much compressed; seen from the side subreniform, highest in the middle ; 

 greatest height equal to about half the length; anterior extremity evenly rounded, 

 posterior narrowed and somewhat obliquely rounded. Dorsal margin boldly arched. 



