'J, It CONTRIBUTIONS PROM llll NATIONAL HERBARIUM. 



omphalos minus Mann, sp. nov. Pi \n \ I \ noi ri i 



Valves circular, the central hyaline area or rosette unequally divided into five 

 pgments by straight or slightly curved partitions, having neither forks 

 nor angular breaks, the focus of 1 1 1 • - ti\ •■ segments being noi in the center of 1 1 1 « - valve, 

 l.ui slightly nearer the Bide bearing the narrow Limb; i 1h ■ wedge-shaped segment of 

 the narrow limb smallest, constituting about L2 per cent of the central area, th< 

 her side larger, each about 20 percent of the area and the remaining two 1. 

 about -i per cent; narrow limb sharply bent to tin- left, dividing the beaded com- 

 partmente on « i 1 1 1* r Bide of ii into two unequal portions; of the four remaining Limbs 

 one or tw-> slightly curved; all four Btout, expanded at the ends anil bearing a minute 

 circular process at the extremity; all five Limbs reaching to within one row of beading 

 <>f tin- margin; beading fine, decreasing t"\var<l the margin; approximately regular, 

 the slight deviation from regularity being repeated exactly in each of tin- pairs of 

 compartments to the righl and left of the narrow Limb. Tin- species i- very abundant 

 in the one sounding where it was discovered and i- constant i" its type. 



Diameter of valve 0.04 t" 0.06 mm.; rows of beading L3 i" L5 in <>. 1 nun. 



Type in the V . S. National Museum, X". 590128, from station 4029H, Berinj 

 Tune '-'7. L900; 913 fathoms, bottom of gray Band and day. 



The nearest form i" this is -1. debyi Pant." Ii differs from the Latter in the character 

 of the beading and in the absence of Beptae joining the dividing lines of the wedge- 

 shaped segments of 1 1 1 « - central rosette. 



Asteromphalus roperianus Grev.) Kali'-, in Pritch. Hist. [nfus. ed. 1. B38. L861, 



Schmidt, Atlas pi. 38./. 15. I s :*'.. Ratt. Proc. Roy. Soc. Bdinb. 16: 657. L889. 



str. Rep. Voy. Chall. Bot. 2: L33. j>l. 5.f. S. L886. Schultze, Bull. Torr. Club 



14: 96. L887. De Toni, Syll. Alg. 2: llll. L894. 



Asterolampra roperiana Grev. Trans. Micr. Soc. Lond. n. >. 8: I If. ///. .;./. /;. I860. 



Moeb. Diat.-taf. pi. SS.f. /;. L890. 

 Uaasterias abyssi Ehrenb. Phys. \l.h. Akad. Wiss. Berl. 1872: 392. pi. 9. J. 7. 



L873. 

 Found ai Btation 2807, Galapagos Islands. 



Asteromphalus shadboltianus Grev. Kali— in Pritch. Hist. [nfus. ed. L. 838. 1861. 

 Schmidt, Atlas pl.SS.f. 17. 1876; pi. 137. f. 16. 1889. Ratt. Proc. Roy. Soc. 

 Edinb. 16: 656. L889. De Toni, Syll. Alg. 2: llll. L894. 



<,hni<i>r(i shadboltiana GTev. 'Fran-. Micr. Soc. Lond. n. b. 8: 121. /</. ;./. /.'<. 

 L860. Moeb. Diat.-taf. pi SS.f. 19. L890. 

 Found at stations 2919, 2920H, 3688H, near Hawaiian [slandsand in Okhotsk Sea. 



Asterom.ph.alus van heurckii Mann. >j>. nov. PLATE XLV, i n.i re ">. 



Valve circular, Bcarcely convex, extremely delicate and translucent; radiating 

 Limbs 12; central hyaline area <> r rosette Large, divided somewhat unequally into 12 

 wedge-shaped Begments by tortuous partitions, tin- segment belonging to the narrow 

 limb alone reaching the center of the valve and narrower than the rot ; Limbs Btraight, 

 slender, terminating at the margin of the valve in suddenly enlarged extremities, 

 bearing a minute process; margin narrow but evidently striated; markings of the 12 

 external wedge-shaped compartments very delicate, appearing under magnifications 

 of 200 to 260 diameters i" consist of delicate parallel Lines concentric with the periphery 

 of the valve but under the highest magnification resolved into lino moniliform striae, 

 those nearest the periphery alone parallel to it. those nearer the center becoming 

 curved in the opposite direction that is. with the convexity inward- the striae 

 slightly wider apart than the width of the beading; the beading next to the limbs 

 separating the compartments and bordering the internal convex ends of the com- 

 partments double the size of the rest of the beading, forming a Bingle row of large 



Bacill. In- 3: pi tl.f.SOS. 1893. 



