M\\\ DIATOMS OF THE ALBATROSS VOYAGES. '2 1 7 



beads around the outer edge of each compartment. Under lovs magnification 

 bordering rows are alone visible, the rest of the compartments appearing to be hyaline. 



Diameter of valve 0.088 .: striae I L2 to 1 L9 in 0. 1 mm. 



Type in the CJ. S. National Museum, No. 590129, from 3tation 2923, oft southern 

 California, January L9, L889; 822 fathoms, bottom of green mud. 



I have named this fine Bpecies as above, nol only because of my high regard for 

 Dr. I It-nri Van Beurck, bu1 also on accounl of its general resemblance to AsU rolampra 

 ran In wrchii Brun. fl 



Asteromphalus variabilis (Grev.) Ratt. Proc. Roy. Soc. Edinb. 16: 655. L889. De 

 Toni, Syll. Alg. 2: I IK). L894. 



Asterolampra variabilis Grev, Trans. M i< r. Soc. Lond. n. s. 8: III. pi. S.f. 6 8. L860. 



My specimen is a rather doubtful example of the above species, and, ii should be 

 added, the species itself is open to some question. 'The figures of Greville in the above 

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

 character of the markings to make it certain thai figures 7 and 8 are nol both 

 ically and specifically di Eferenl from figure 6, their general aspecl being that of Astero- 

 lampra, as Greville has of course named them. There is no question about figure 6 

 being an Asteromphalus; and Rattray is probably justified in putting this variable dia- 

 tom under the above name. My form lends confirmation to this view, the segment of 

 the central area belonging to the narrow limb, being, as in figure 6, wedge-shaped and 

 the valve having all the characteristics of this genus. Its size, also, and the fineness 

 of its striation correspond exactly with those data as given by Rattray. 



Diameter of valve 0.113 mm.; striae 5 to 8 in 0.01 nun. 



Found at .-union 1029H, Bering Sea. 



TBJPODISCUS Ehrenb. 



Tripodiscus Ehrenb. Phys. Abh. Akad. Wiss. Berl. 1839: L30, L59. pi. S.f. 6a-c. 

 L841. 



Tetrapodisais Ehrenb. Ber. Akad. Wiss Berl. 1843: L66. is 11. Ktttz. Bacill. L36. 

 pi. l.f. 6. is 1 1. 



Pentapodiscus Ehrenb. Ber. Akad. Wiss. Berl. 1843: L66. L844. 



Podiscus Bail. Am. Journ. Sci. 46: L37. pi. S.f 1 2. L844. 



Eupodiscus Ehrenb. Ber. Akad. Wiss. Berl. 1844: 73. L845, in part. 



Aulacodiscus Ehrenb. Ber. Akad. Wiss. Berl. 1844: 73. L845; Mikrog. pi. is. 

 1854. Pritch. Eist. [nfus. ed. L 843. pi. 6. f. 4 ■>■ l s, d. Char. Emend. Ratt. 

 Journ. Roy. Micr. Soc. 8: 337. L888. De Toni, Syll. Alg. 2: L091. L894. 



The name Tripodiscus is clearly prior to the generally accepted name Aulacodiscus. 

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

 accidental number of three processes, whereas nine-tenths of the members of the 

 genus have from four to twenty processes. But the descriptive exactness of a name 

 can be ii" criterion of its claim in taxonomy, h is, however, genuinely unfortunate 

 that this inapt name must, according to existing rules. Bupplant the better and gener- 

 ally known name Aulacodiscus. Tripodiscus is clearly defined as a genus& and its 

 type species. '/'. argus, c \< equally definite and is unmistakably figured. On the plate 

 it is called '/'. germanicus, bu1 the reference to it on page L59 gives preference to T. 

 argus. Bailey's name. Podiscus, is better than either of the Eoregoing, bo Ear as aptness 

 is concerned. The Bpecies T. argus, generally known as Eupodiscus argus Ehrenb., 

 is hardly characieri.-t ic of the genus, as on account of its imperfectly radial ing areola- 

 fcion and its double markings it represents, together with '/'. {Aulacodiscus 



"Mem. Sue. Phys. ei Hist. Nat. Geneva 81 1 : 19. pi. /.../'. /. L891, 

 b Phys. Abh. Akad. Wiss. Berl. 1839: L30. L841. 

 cOp. cit. 159. pi 



