302 BULLETIN OF THE 



Smith in his text correctly describes the peculiarities of this species, but the 

 figures on Plate IX., referred to as Neoera claviculata, though intended as rep- 

 resentations of this species, have not a clavicle ! It seems that the " artist," 

 though warned, took it upon himself to omit this feature (!), and succeeded, in 

 spite of Mr. Smith's instruction" to the contrary. 



(Genus?) MYONERA Call and Smith. 



Shell without cardinal or lateral teeth in either valve; with or without a 

 buttress; fossette vertical or posteriorly directed, attached to the hinge by 

 either edge; sculpture radiating or concentric. Type Necera paucistriata 

 Dall. 



Necera sulcifera and angularis Jeffreys, lamellifera Dall, limatula Dall (-H 

 contratta Jeffreys), laticella Dall, undata Verrill, and fragilissima Smith, be- 

 long here. The group comprises Sections L and M of Smith, the difference 

 between which, judging by the figure of fragilissima, does not seem to be very 

 great. 



The absence of gills or palpi, if confirmed by the study of fresh specimens, 

 ia a very remarkable feature of this and the preceding groups. 



Myonera paucistriata Dall. 

 Necera paucistriata Dall, Bush, Trans. Conn. Acad., VI. p. 473, 1885. 



Shell closely resembling Tropidomya abbreviata Forbes, externally, but 

 deeper, lai-ger, with the anterior concentric sculpture more pronounced, and 

 two strong keels posteriorly, one a little before and the other a little behind 

 the place where the single keel of abbreviata is placed. The concentric sculp- 

 ture ceases just before the anterior keel ; the space between and behind the 

 keels is smooth except for lines of growth or a few faint radiating striae. The 

 epidermis is pale, filmy, and polished, except on the dorsal margin and toward 

 the end of the gaping rostrum, where it seems to concentrate a little ; umbones 

 rather prominent, whole shell plump, thin, extremely fragile; interior polished; 

 rib faint; no distinct buttress; fossettes good-sized, extending obliquely pos- 

 teriorly; attached by most of the posterior edge to the margin above; ossicle 

 lingniform, smooth, narrow; hinge smooth and edentulous in both valves. 

 Max. Ion. lO.O; max. alt. 8.5; max diam. 6.5 mm. 



Habitat. Stations 226 and 230, near St. Vincent, in 424 and 464 fms., sand, 

 bottom temperature 42°.5 and 41°.5 F. Specimens living, but smashed. Also 

 at Station 43, near Tortugas, in 339 fms., bottom temperature 45°.0 F., living 

 but broken. 



This very lovely species resembles externally T. abbreviata, which has one 

 keel; Myonera angularis Jeffr., which has two keels more posterior than in 

 this species; and Myonera undata Verrill, which has no keels, and is much 



