KONOL. SV. VET. AKADEMIENS HANDLINtiAU. HANI) 26. NM) 2. 



71 



,, j V. very convex P. crucijix 15k. a. Tkmp. 



\ V. less convex 4. 



I Stri;i; coarsely iiunctato P. jiigafu (Ji,. 



■ I - liiRJy — P. Htauroptera Batt,. 



1. P. impleta Cl. a. (tRove (1891). — V. elliptic-lanceolate. L. 0,i3; B. 0,038 mm. Median 

 line with very ap])roximate central pores and indistinct terminal fissures. Stanros narrow dilated 

 at the extremities. Striic 12 in 0,o i mm., radiate throughont, finely lineate. Longitudinal lines 3 

 to 4 on each half of the valve, the most distinct connecting the ends of the stauros wifh the ends 

 of the valve. — Nav. impJ. Cl. a. TtROVE. Diatomiste I, p. r)8 PI. IX fig. 1. 



Marine: Macassar Straits! 



2. P. polj'J^oiisi Brun (181)1). — V. broad with slightly convex margins and cuneate, obtuse, 

 ends. L. 0,i-i to 0,1.-,; B. 0,035 to 0,0.-) mm. Median line with small terminal fissures, turned in 

 the same direction, and not very a^iproximate central pores. Stauros moderately broad. Strise 

 slightly radiate throughout, 1(5 in 0,01 mm., punctate, puncta 21 in O.oi mm. Longitudinal lines 

 not very distinct. — Nav. pol. Brun. D. Esp. n. p. 38 PI. XV f. 5). 



Marine: Japan, fossil! 



The longitudinal lines are not so distinct as on the 

 other species. In their place is a kind af low crest sepa- 

 rating the interior part of tlie valve from the exterior 

 steeply sloping part. 



3. P. staiiroptera Bail. (1854). — V. elliptic-lanceo- 

 late, with obtuse ends. L, 0, 11 to 0,i3; B. 0,03 to 0,o3r> 

 mm. Staurcts moderately broad. Strife 14 to 18 in 0,01 

 mm., finely punctate, parallel. Longitudinal lines distinct, 

 median. — Amphorti stanropfcra Bail. Smiths. Contr. VII 

 p. 8 f . 14, 1') (1854). Amphiprora lepidoptera Greg. D. of 

 Clyde p. oOf) PI. XII f 59 c (1857). Aviphiprora obsxsa 

 Greg. D. of Clyde 1. c. fig. 60. A. S. N. S. D. Ill f. 1. 

 Nav. arctica Cl. D. arct. S. p. 1(> PI. Ill f 13 (1873). 

 Lagerst. Boh. D. p. 46. Cl. N. R. D. p. 13. 



Marine: Sea of Kara (Grun.). Finmark! North Sea! 

 Nova Scotia (Bail). Sidney (Brun Coll.!). 



4. P. jiigata Cl. (1881). — V. lanceolate, with olv 

 tuse ends. L. 0,o68 to 0,093; B. 0,o2 to 0,024 mm. Stauros 

 of median breadth. Striie 10 in 0,oi mm. parallel, more distinct outside the longitudinal lines, 

 distinctly punctate; puncta about 12 in 0,01 mm. Longitudinal lines median. — Nav. jiKjata Cl. 

 N. R. d". p. 13 PI. Ill f. 38. 



Marine: Galapagos Islands! 



Var. Frnsacolre Cl. (1881). — V. slightly triundulate, with subrostrate ends. L. 0,o.'i4; B. 

 0,01 r,. Stria; 15 in 0,oi mm. — Nar. Pensacohf Cl. N. R. D. p. 14 PI. Ill f. 39. 

 Marine: Pensacola! 



5. P. crucifix Temp. a. Brun. (1889). — V. vei'y convex, narrow, lanceolate, with subacute 

 ends. L. 0,12; B. 0,u22 mm. Stauros moderately bi'oad. Strice 16 in 0,oi mm. parallel, punctate; 

 puncta about 16 in 0,oi mm. Longitudinal lines marginal. — Nav. criic. D. foss. du Japon p. 42 

 PI. VII f 10. 



Marine: Japan, fossil! 



P. sfauropfcra 500 times magnified. 



