RECENT BRITISH OSTRACODA. 



117 



minates in a conspicuous elevation over the anterior hinge ; posterior margin sti 



and much ernarginate. The dorsal margin slopes pretty evenly backwards from the 

 anterior hinge; the ventral margin nearly straight, hut hearing a variable numhcr of 

 regularly set, short, hlunt teeth. Outline, as seen from above, somewhat cuneate, 

 uddenly narrowed "behind, hroadest at the posterior third ; width equal to nearly brill' 

 the length. End view suhquadrangular. The surface of the shell is rugose, and bear 

 three rows of elevated processes, or truncated spines ; one row commences at the anterior 

 hinge, running parallel to and within the anterior and ventral margins nearly as tar a 

 the posterior extremity; a second row runs directly backwards, almost in the in. iian 

 line of the valve ; a third and much less conspicuous row runs transversely, parallel to 



■ 



and just within the posterior margin. Animal unknown. 



Length ^5 in., height 



»/ 



(Mi 



31. Cythere antiqtjata (Baird). (Plate XXX. figs. 17-20.) 



Cytherels anliquata, Baird, Brit. Entom. p. 1 "6, tab. xx. fig. 2. 



British type. Distribution : Recent— Great Britain, Ireland, Bay of Biscay, Levant. WW— Glacial 



clay and raised beaches, England, Scotland, and Ireland. 



Valves rectangular, quadrilateral ; length equal to twice the height. Anterior border 

 rounded at the angles, and armed below with a series of hlunt spines; posterior margin 

 rectangularly truncate, and bearing below the middle several strong lmgu.form sp,n. . 

 Dorsal and ventral margins parallel, the latter quite straight, the former cleft into three 

 or four segments with intervening sulci. The carapace, as seen from below, is oblong. 

 with projecting lateral ate, which taper towards the front, but terminate abruptly behind. 

 giving to the whole a somewhat arrow-headed outline. Seen from above the outline , 

 more irregular. End view subjugular, deeply ernarginate below , each Wars! porhon 

 with two strongly projecting ridges. The surface of the shell is tabereoWe. «db« , 



* • i i i I L*A Limtiidinil ridges, which terminate abruptly in angular 

 two conspicuous, sharply defined longitudinal iiu D «, w ™ r f, >rM rp.1 at 

 elevations near the posterior extremity of the valve. These ribs are m, tl pmf oi a 

 the base, the rows of apertures thus produced being very im ^££r£ 

 aspect of the shell (fig.'lO). The anterior ^^-J^jJ ^KTd 

 Left valve, lav<,<,r than the rieht. Upper antennae nvejomtea, j 



pines straight 



slender ; second Joint equal in length to the followmg ^JT^Ki of 

 and slender. Second Joint of lower antenna, very ^^Xwing two term 

 third joint. Second joint of the last foot equal m length to the t U „ 

 -law very long and slender. Abdominal lobes terminating m a short seta. 



.Length sV m., height - 5l) - in. } Q Je ff reys ) . Tobermory, at ro fc> 



Hob. In depths of 7 to 60 fathoms. Hebrides and the urn ^ \ ^ Nomtm ) . \berd< ire i ast (Mr. 

 o? Laminaria ; Shetland, Isle of Skye, and Plymouth (Met . . '\^ p Robertson}; Birterbuy 



Dawson) ; Oban, Ormeshe 



Bay, dredged, and in oyster-ooze from Stranraer ,. • ./ , ^ ^.^ 



l n » M \ d«._j.* (T>„ JlonrlA. and Cowes (J//.i- <" " 



>/■ 



1 



hues) , Roundstone (Dr. Alcock) , and Cowes 

 51 fathoms (Admiralty soundings) . 

 VOL. XXVI. 



3 



