374 CO^nTRTBUTIONS rilOM TPIE NATIONAL HKKBAHIUM, 



aidi' uf oarli ap(.^\J (:iir\uig .^lightly tu that side, then recurving toward Uu^ ventral side 

 in a lung, graceful arc and terminating at a small, rectangular^ hyaline central area, 

 close to tho ventral i=ide; markings of clos(4y set, nKtniliiorni t^triae, transverse except 

 toward the apices^ wlu^-e they are sHgluly inemved ; luading ;)f ihe striae alike on l»nth 

 sidi'sof llie raphe, "wliirh is bordered on each sidt^ l)y a narrow liyalin<^ space; a hyaline 

 line, the width of one row^ of beads, forming a narroAv slauros transversely across the 

 center, from the rix'tangular central area ttt the dorsal sid(\ 



Length of valve, 0.J35 mm.; widtli of valve, 0.023 nun. Striae. 70 in 0.1 jum. 



Type in the U. >S. National Museum, no. 590153, from station .SOSSIL Okhotsk Sea, 

 August 27, 1890; 1,5(52 fathoms, bottom of brown mud and fine sand. 



There is some resemblance between the above and A . elajans Gregory ; ^^ but Gregory's 

 species is more attenuated, especially as to lln^ apicc^s, and is nuicli more delicately 

 marked. Thus De Toni says of il,^ "Valvis gracilil>us, semilunatis, 1( vibus (striis 

 obsolotis)." It resembles mure strongly^, levu Gn^gory,^ a simihu-ity whicli is, how- 

 over, accidc^ntal to Schmidt's figure, as can bo seiMi by comparing it with thcM^riginal 

 d(^scrii)tion and figures,^ Gregory saying that his form is " very hyaline/' nnd that ''the 

 striae are very fine, about 00 in 0.001, very hyaline^ and hardly to be seen with a power 

 of -100 diani/' Schmidt's figure is therefore quite deceptive. 



Amphora crescens Mann, sj). nov. Platk 3^LIV, ficvhe 3. 



Ai)\phora crassa p^nicfala Grun.? Schmidt, Atlas pL :!S.f. 32. 1875. 



Valve slightly conv<^x on tlie dorsal side, more nipidly curving toward tlie rounded 

 and im^urved ends; tlu^ margin appearing ribbed because of llu' transv(M-s(^ striae; ends 

 belli inward into round(^<l wings extending ])eyond the ventral line of the rest of the 

 valv(^ and hyalim^ along tlieir inner edges; raphe beginning near tlie t^nds, close to the 

 dursal margin, alnujst straight until iiear the middle, then curving xcnt rally to the two 

 ci'utral nodulesj wliich are distant from the ventral side on(^-fuurlh the width of Ihe 



■ 



valve; ventral marginslightly convex at the center, straight or slightly (*oncave between 

 this antl the rounded enils; transverse striae obscure, except where seen in rebef along 

 the dorsal margin; markings different on the two sides of the raphe; on thedorsal side 

 ct>nsisting of rows of beads, three to five in a row, the smalh^st next to and touching ihe 

 raping increasingregularly insize tothelast at thedorsal margin; these rows all erna ting 

 with thestria<M'isiblo at the margin, equidistant, 44 in 0. 1 nun., transverse at the cen- 

 ter of tln^ valve, thence outward gradually inclining toward llie ends; on the ventral 

 side tlie nnvs sliorter, of two or three heads of nearly equal size, those nearest the raphe 

 sliglitly larger; not touching the raphe, but uniformly distant the width of one bead, 

 thus leaving a hyaline line along the raphe on the ventral side only; rows absent at the 

 middli' for the width uf two row^s, thence at Jirst inclining from the central area, half- 

 way to their bectmiing transverse, from there outward gradually inclined from the 

 ends, thus making them at this point confluent wuth those on the dorsal side of the 

 raphe; at theroiuided eiuls of the valve tlie venlral rows not reaching the margin, but 

 leaving tliese hyaline on their inner edges. 



Length of valve, 0.01) mm.; width of valve, 0.013 mm. Head<Hl striae, 44 in 0.1 mm. 



Type in theU. S. National Museum, no. 590158, from station 4510H, Gulf of Cali- 

 fornia, December 22, 1904; i, 027 fathoms. 



This species bears a significant general resemblance to the figure in Schmidt's Atlas, ^ 

 named A. crafisa punctata Grun. The figure is very poor^ innking it imp(.)ssible to see 

 wheth(^r or not there are beaded striae present, though the varietal name implies that 



" Trans. Rlicr. Soc. Lond. n. s. 5: 70. pi. l.J. SO. 1S57. Mueb. Diat.-taf. pi, 12. f. 30, 



1890. 



^ De Toni, Syll. Alg. 2: 381. 1891. 

 c Schmidt, Alias, pi. 26. f. 9. 1S75. 



[d Trans. Roy. Soc. Edinl>. 21: 514. pL 12./. 74, b-c. 1857, 

 « PL 28J.32, 1875. 



