MANN DIATOMS OF THE ALBATROSS VOYAGES. 277 



beadn aroiiiul llie outer edge of eadi coinpartment. T^iidrr low inagniliratiotis these 

 boixhiiiig rows are alone Yi.sii)l(^j the rest of the coniparl nu'iits appearing to Ix? liyaline. 



Diameter of valve 0.088 nun.; striae ]12 to 119 in 0. 1 mm. 



Typr in the U. S. National Museum, No. 590129, from station 2923, off southern 

 California, January 19, 1889; 822 fathoms, bottom of green mu(L 



I have named this fine species as above, not only Ijecause of my liigh rrgard for 

 Dr. Henri Van Ileurck, but also on account of its g<^noraI resemblance to Aalerolavvpra 

 van heiirckii lirun.'^ 



Asteromphalus variabilis (Grev.) llatt. Proc. Roy. Soc. Edinb. 16: 055. 18S9. De 

 Toni, Sylh Alg. 2; 1410. 1891. 



AsLct olampra variahilis Grvv. Trans. Mier, Soc, Lond. n. s. 8: 111. 2>Z. 3,f, 6-8, hSdO. 



My specimen is a rather doubtful example of the above spt^cies, and, it should bo 

 addedj the species itself is open to some question. Tlu^ (igur(?s of Gn^ville in the above 

 citation are too incomplete as to tlie nature of the limbs and especially as to the 

 character of the markings to make it certain that figures 7 and 8 are not both gourr- 

 ically and specifically differ(*nt from figure 6, their gonc^ral aspect being that of Ast(To- 

 Iami>ra, as Greville has of course named them. There is no (question about figure G 

 being an Asteromphalus; and liatlruy is probably jlL^lified in putting this variabhi dia- 

 tom under the above name. My form lends confirnuuion in iliis view, iho segment of 

 the central area l^elonging to the narrow liml>j Ix^ng, as in figure 0, wedge-shaped and 

 tlie valve having all the characteristics of this gemis. Its si^^e^ alsOj and the iiiieiiess 

 of its striation correspond exactly with 1hose data as giv(m by Kattray. 



])iaineter of valve 0,113 mm.; striae 5 to 8 in 0.0). mm. 



F'jund at station 402911, Bering Sea. 



TRIPODISCUS Ehrenb. 



Tripodiaciis Ehrenb. Thys. Abb. Akad. AViss. P>erl. 1839: 130, 159. pi S.f, fia-c. 

 184 I . 



TcLrapodtscfKs Ehrenl). Ber. Aka<l. AViss Berk 1843: KHI. 1S44. Kiitz. Baeill. 130. 

 pi. I.f. (L 1844. 



Peniapodi^nis Ehrenb. B(>r. Akad. W iss. Berk 1843: IGfi. 1844. 



Podiscus Bail. Am. Jeurn. Sci. 46: 137. pL S.f. 1-2. 1844. 



Eupodiscus Ehrenb. Ber. Akad. \\'iss. Berk 1844: 73. 1845, in part. 



Aulacodhscns Ehrenb. Ber.^Akad. Wiss. Berl. 1844: 73. 1845; Mikrog. pi. tS.f. 47, 

 1854. Pritch. Hist. Infus. ed. 4. 813. pi. 6. /. 4-S, ISGL Char. Emend. Bait. 

 Tourn, Roy. Micr. Soc. 8: 337. 1888. De Toni, Syll. Alg. 2: 1091. 1891. 



The name Tripodiscus is clearly pri<jr to the generally accepted name Aulacodiscus. 

 It is an unfortunate; name, as it applies strictly to only those specimens that have^ the 

 accidental numl>er of tliree processes, whereas nine-tenths of the members of the 

 genus hav(^ from four to twenty proc(^sses. But the descriptive exactness of a name 

 can be no (Titerion of its claim in laxtmomy. It is, however, genuinely unfortunate 

 that this inapt name must, accorcHng to existing rules, supplant the better and g<^ner- 

 ally kTiown name Aulacodiscns. Tripodiscus is clearly deline<l as a geiuis ^ and its 

 type speci(^s, T. argus,<^ is equally definite and is unmistakably figured. . On the plate 

 it is called T. gennanicus, but the reft^rence to it on page 159 gives preference to 1\ 

 argiis. Bailey's name, Podiscus, is better than either of the foregoing, so far as aplncss 

 is concerned- The species T. argns, generally known as Eupodiscus argus l^hrenb., 

 is hardly characteristic of the genus, as on account of its im]>erfectly radiating areola- 

 lion and its double markings it n^presents, togi'tluT with T. {Aulacodiscus) rogcrsii 



cMem. Soc. Phys. et Hist. Nat. Geneva 31': 19. pL I}./. 1. 1891. 

 ^Phys. Abb. Akad. Wiss. Berl. 1839: 130. 1S41. 



<^ Op. cit. 159. pi. S.f. (ia-c. 



