of the Fishery Board for Scotland. 323 
ventral margins nearly straight, the former is slightly convex towards the 
‘i anterior extreinity ; anterior margin evenly rounded, posterior extremity 
‘y with a Short beak situated about the middle, its tonilimation narrow, 
4 truncate. Seen from above, ovate, slightly constricted in front, where the 
| valves meet. At the posterior end, the middle is bluntly mucronate, and 
; the sides are produced toan acute anvle, so as to impart to it a somewhat 
tridentate appearance ; dorsal ridge prominent, where it bends downwards 
infront. Surface sculptured with flexuous longitudinal riblets, crossed by 
-  @ few indistinct ones arranged irregularly. Length, -5 mm.; breadth, 
length; height, fully 4 the length. 7 
ho _ Habitat.—Off St Monance, in 12 to 14 fathoms, bottom sand and 
eravel, rare. 
: - This species somewhat resembles Cytherura acuticostata, but differs in 
heing not so stout, and in having the valves produced backwards, so that, 
the posterior extremity of the shell has a tridentate form. 
: Oytherura mucronata, n.s. (Pl. XII. figs. 3, 5). 
Shell seen from the side, elongate, narrow ; height about equal at both 
Brae, length two and a half times the height ; dorsal margin nearly straight, 
ventral margin slightly and evenly concave, “posterior end much produced 
and wedge- shaped, forming a ‘ beak,’ which is situated below the middle ; 
_ anterior margin broadly rounded, somewhat produced in the middle. 
Seen from above, oval, with the ends acuminate ; the margin at each end, 
; especially the anterior margin, is produced, so as to form a distinct 
‘mucro.’ The surface is marked with indistinct raised lines, which are 
somewhat irregularly distributed ; the breadth is equal to the height; 
length, -33 mm. 
Habitat.—Off St Monance, not very rare. 
Cytherura simplex, Brady and Norman. 
Cytherura simpex (name only), Brady and Robertson, Ann. and 
Mag. Nat. Hist., ser. iv., vol. xi. p. 66 (1872). 
Cytherura sarsit (“local variety ’ ’), idem ibidem, vol. xiii. p. eee 
pl. iv. figs. 6, 7 (1874). 
Cytherura simplec, Brady and Norman, op. céé., p. 200, pl. xviii. 
figs. 1; 2. 
Habitat. —Off St Monance, frequent, depth 12 to 15 fathoms ; bottom 
clean sand, part gravel. Viewed laterally, the shell of this species differs 
somewhat from the usual- form of Cytherura, which has a more or less 
distinct ‘beak’ at the posterior end, whereas this has no posterior beak. 
New to the east of Scotland. 
i“  Oytherura fulva, Brady and Robertson. 
wy’ Cytherura fulva, Brady and Robertson, Ann. and Mag. Nat. Hist., 
ser. iv., vol. xiii. p. 116, pl. iv. figs, 1-5 (1874). 
Cytherura fulva, Brady and Norman, op. cit., p, 205, pl. xix. figs. 
9-11. 
oeigbitar. —Largo Bay and other parts of the Estuary, but not common, 
ON ew to the east of Scotland. 
| Ggtheropteom punctatum, Brady. 
_Cytheropteron punctatum, Brady, op. cit., p. 449, pl. xxxiv. figs. 
8. 
¢ 
»* jo 
_ - 
as 
- Cytheropteron punctatum, Brady and Norman, op. cit., p. 211. 
So endiea —Off St Monance, rather rare. I do not find any previous 
Fecord of this species for the east of Scotland. 
