516 DE G. S. BRADY ON 



Only one example of this species was found in the Noumea dredging, but the genus 

 was already familiar to me from specimens dredged in the North Atlantic, but not yet 

 described. The very much produced extremities and the twisted form of the shell are 

 quite characteristic. 



Genus Sarsietta, Norman. 

 (British Association Report, 1868, p. 292.) 



Sarsiella scutyta, n. sp. (PI. I. figs. 17-20). 



Shell, seen from the side, subcircular, height and length nearly equal. Anterior 

 extremity flattened, truncate, having a wide triangular prominence above, and a 

 similar but less pronounced process below ; posterior extremity rounded and bordered 

 with a more or less regular series of small nodular prominences; dorsal margin arched, 

 sinuated at its junction with the posterior border; ventral convex, generally somewhat 

 crenulated. Seen from above, the outline is subcuneiform, wide and truncated behind, 

 with a prominent median beak, obtusely pointed in front, the sides parallel behind the 

 middle, but converging gradually towards the front. Surface of the valves undulated, 

 marked with closely-set small excavations, and having two stout flexuous ribs running in 

 a longitudinal direction from near the triangular prominences of the anterior margin. 

 These ribs are in some cases lost near the centre of the valve, and sometimes stretch over 

 nearly its whole length, and there are often numerous smaller ridges running in a radial 

 direction from the circumference of the shell inwards. Length 1 *4 mm. 



Habitat. — Noumea, dredged in 2-4 fathoms ; Levuka, between tide-marks ; Vuna 

 Point, Taviuni, between tide-marks. 



This appears to be a not uncommon species of a group which, judging from the 

 evidence of these gatherings, is much more strongly represented in the Southern than in 

 the Northern Hemisphere. Almost nothing was seen of the soft parts of the animal. 

 The very variable sculpturing of the shell— no two specimens being exactly alike 

 in this respect — seems to depend partly on age and partly, perhaps, on sex. The 

 figure 18, having been drawn from a gaping shell, gives an incorrect idea of its width. 

 The description above given applies to specimens of the type figured in PI. I. figs. 17, 

 18 ; but in a dredging from off Cap Bon Louis, New Caledonia, there occurred two 

 specimens, differing very considerably from the types, but which from their general aspect 

 and the close similarity of sculpture, appear to be, if not the same species, at any rate so 

 closely related that I cannot find any satisfactory distinctive characters. One of these 

 specimens is figured in PL I. figs. 19, 20. 



Sarsiella simplex, n. sp. (PI. IV. figs. 15, 16). 



Shell, seen from the side, almost circular, with a large median beak-like process 

 behind ; length and height (exclusive of the beak) equal ; beak subtriangular, truncated at 

 the apex. Seen from above, the outline is lozenge-shaped, widest in the middle, twice as 



