1S94. PROCEEDINGS OF THE NATIONAL MUSEUM. 685 



in strength i)eriplierally, and with much wider interspaces; on the base 

 are five more beside the umbilical carina. The peripheral ridge is the 

 highest and the suture is applied against it, the interspace below the 

 perii^heral ridge is a little wider than the others; on the spire the trans- 

 verse sculpture comprises numerous obliquely radiating short ridges 

 which cross the spirals at regular intervals and extend more than half 

 way across the adjacent interspaces; these radii are not continuous 

 over any two si^irals bnt alternate on the successive single spiral ridges, 

 rising to a sharp point where they cross, the upper series beginning 

 close to the suture; on the base the umbilical carina is marked by a 

 strap-like tiat rib across which lie close-set rectangular knobs from 

 which radii extend continuously or nearly so to the outer basal spiral, 

 with an intercalary set of radii appearing somewhat irregularly as the 

 interspaces widen toward the periphery; inside the wide scalar umbil- 

 icus the radii are continued as vertical, close set lirte, only interrupted 

 by an obscure spiral ridge just below the internal sutural line; aper- 

 ture oblique, subqiuulrate, crenulated by the sculpture, the margins 

 sharp and thin, the body with a thin wash of callus, the throat pearly 

 and smooth where not angulated by the sculpture; the pillar lip not 

 differentiated ; epidermis pale straw color, extremely thin with a slightly 

 silky luster; height of shell, 7; maximum diameter, 10; minor diameter, 

 8 mm. 



Station 3475, in 351 fathoms; temperature 43° F. Ko. 127121, U. 

 S.N.M. 



The sculpture is something like that of Trochus illoUts, Watson,* but 

 the form of the shell is diflerent. It belongs to the group of T. a'(/lecs 

 Watson and Solariella actinophora, Dall. 



GeuuB EMAEGINUL A, Lamarck. 



EMARGINULA HAWAIIENSIS, new species. 



Plate XXVI, tig. 7. 



Shell large, thin, recurved conical, slightly wider behind than in front ; 

 of an ashy cream color, but probably white when fresh; nucleus lost; 

 apex small, recurved, pointed, somewhat laterally compressed; anterior 

 slope gently arched; posterior slojie straight or possibly a little concave, 

 shorter than the anterior; outline of the base evenly rounded; sinus 

 narrow, one-fourth as long as the whole anterior slope, set in to the 

 right of the middle liue of the shell, its limbs tending to approach 

 anteriorly; fasciole narrow, marked by close-set semicircular elevated 

 ripples, concave forward; sculpture of close, even, regularly distributed, 

 elevated threads, radiating from the apex with smaller intercalary 

 threads toward the margin ; these are crossed by even, regular, elevated 

 concentric lamellte, slightly nodulous at the intersections ; at the margin 

 of the shell the major radials are slightly more than a millimeter apart 



* Challenger Gastr., pi. xvii, tig. 3c. 



