.MANN DIATOMS OF THE AJLBATROSS VOYAGES. 269 



incidentally on the anastomosing of the shadow linea near its center, we certainly 

 recognize a difference as small .1- is consistent with any distinction al all. There i- 

 excuse for this in the fad thai all members of this genu* are closely allied and differ- 

 ences may 1>»' recognized to divide up the large number of its forme which elsewhere 

 would hardly Berve thai purpose. Bu1 having made thh admission, there is nothing 

 left mi which i" base a distinction between Greville's S. johnsonianus and those 

 quoted above as Bynonyms. Triceratium jeremianum ie Bimplj a polygonal instead 

 of a circular specimen of the same diatom, and this divergence, being .1 mosl 1 ommon 

 one in the genus, counts for nothing. So S. caraibicus has a few more beads than the 

 triangular examples of - s '. johnsonianus on 1 he sanie plate. The " Bpiral arrangemenl " 

 of ilic beads in S. truani, its only distinction, is difficult to detecl and of no worth 

 when del cci c(l. The figure of ' S '. radiatus is almost as fine a copy oi Greville's original 

 figure of S. johnsonianus as could be asked for. Other forms mighl 1"- added to the 

 above list, as their differences arc <a somewhal questionable weight; as >'. pulcfo llus 

 Truan & Witt, 6 S. grunowii Truan & Win.' S. affinis Castr.,d S. trigonus Castr.,< 

 8. margaritaceus CastrJ A little further removed, solelj by the character of the 

 border, is S. californicus Grev., together with a number of ii- Bynonyms.0 



1 have united a large number of circular and triangular specimens under this species, 

 mounted specimens of which accompany this report. 



Found at Btations 2807, 2808, 2920H, 3008H, 3604, 1029H, Galapagos [slands, Hawai- 

 ian Islands. 



Stictodiscus kittonianus Grev. Trans. Mi< i\ Soc. Lond. n. s. 9: 77. pi. i<>. 1 

 L861. Moeb. Diat.-taf . pi 4. f. 2-3. Schmidt, Atlas pi 74. f. 16 18. 1882. DeToni, 



Syll. Alg. 2: L315. 1894. 

 This delicate form, no1 infrequent in the fossil deposits of Maryland and Virginia, 



has been found on the Pacific slope only in the fossil beds of Monterey, California. 



The specimen discovered by me ••ani«' from Bering Sea, north of the Aleutian [slands. 

 Pound at station 1029H, Bering Sea. 



ACTINOPTYCHUS Ehrenb. 



Actinoptychus Ehrenb. Phys. Al.h. Akad. \\ r iss. Berl. 1841:400, 109. pi 1. /../'. 27. 



111. a. L843; Am. Journ. Sci. 46: 300. L844. 

 Actinocyclus Ehrenb. in pari: Bail. Am. Journ. Sri. 45: pi .'./. 11. 1842. 

 Omphalopelta Ehrenb. Ber. Akad. Wiss. Berl. 1844: 270. L845, in part. Castr. Rep. 



Voy. (hall. Bot. 2: 129. pi ;../'. .'. L31. pi. 18. f. 9. L886, in toto 

 Heliopelta Ehrenb. Mikrog. pi S3. Will. f. 5. 1854. Johnst. Quart. Journ. 



Mid-. Sci. 8: I:'., is. L860. Rail's in Pritch. Bist. Ini'ns. ed. I. 840. L861. 

 Halionyx Ehrenb. Mikrog. pi S5A. XXL f. 12. L854. .Ian. Al.h. Schl. Ges. Vaterl. 



Cult." 1861-': pi. /../'. /. 1861; 1862'-': pi la./. 6. 1862. 

 Actinophaenia Shadb. Trans. Micr. Soc. Lond. n. s. L6. L854; Quart. Journ. Micr. 



S.a. 8: 94. pi 6.f. is. L860. 

 Schuettia !)«■ Toni, Syll. Alg. 2: L395 96. L894. 



Closely allied to the above genus are Debya Pant., Anthodiscus Gr. & St., Lepido- 

 discus Win. Actinodictyon Pant., Wittia Pant. They fall into II. I..' Smith's family 



mi. Truan A Win. Diat. Hayti pi ■',./. 9. 1888. 



''Truan & Will. Dial. Hayti L'<>. pi S.f. 5. 1888. 



< <>p. cit. pi ,. /". 25, pi. 5.f. >. pi 6. J. 31. 



dCastr. Rep. Voy. Chall. Bot. 2: I L9. pi t. < 1886. 



' Op. <ai. 122. /</. 31. f. 1. 



'Op. cit. L20. pi 17. f. /.'. 



fifTrans. Micr. Soc. Lond. n. s. 9: 7!>. />/. m. f. 1. L861. 



