Mr. (L Mereschkowsky on CaUfornian Diatoms. 5()5 



observations, pointing out that some, but not all, arc to be 

 looked upon as the traces of ruilimentary hairs. For instance, 

 Dr. A. Fjc-lstrup, of Copenliagen (Zool. Aiiz. xi. p. 14, 1888), 

 writes as follows: — " Bei den ineisten in Midvag gelii Iteten 

 Globiocephalen zeigte die Haut, zutnal in der Unter- und 

 OKerkifferregion, cine Menge kreistorniigcr Porenfiguren, in 

 Giosse und Anordnung individuell selir verschicden. Die 

 Kreise liaben nieistens einen Diameter von '.5-1 cm., einzelne 

 bis iiber 1*5 cm. Die Anzahl der Poren in jedera Kreise variirt 

 der Grosse gemtlss von etwa 20-50; ihr Diameter ist durch- 

 schnittlich "IG mm. Es finden sich sowohl unvollstiindige, 

 sich schneidendeoder beinaheconcentrische Kreise als verein- 

 zelte Poren." The general description of these structures, 

 their size, the manner in which tlie circles intersect or overlap, 

 their irregular arrangement, in various parts and on some 

 individuals only, and the further statement that no sign of 

 them is visible in the foetus, all incline me to think that here 

 also we have to do with scars left by a cuttlefish. Similar 

 structures have evidently been observed in Olobiocephalus by 

 Bennett, quoted by Eschricht and again by Fjelstrup : — 

 " On the head, and chiefly around the lips, the skin is marked 

 with many scattered circles, each the size of a sixpence, and 

 composed of a single row of small depressed dots, which 

 would appear to mark a disposition to the formation of 

 vibrissas or whiskers.^' 1 need hardly repeat that I do not 

 agree with this interpretation of their cause. 



LXV. — A List of CaUfornian Diatoms. 

 By C. Mereschkowsky. 



'Concluded from p. 480.^ 



133. Campylodiscus Thuretii, Breb. J^an Pedro, Monterey, 

 not rare. [M.] 



134. Striatella unipunctata, Agardh. San Pedro, Monterey, 

 not rare. [^1-] 



135. Rhabdonema lineare, Mer. Common in Northern Cali- 

 fornia ; Monterey, rare; San Pedro, very rare. [M.J 



This species has been described and figured in my paper 

 "On Polynesian Diatoms " (see chapter iv.). 



136. Rhabdonema, sp. ? (PI. V. figs. 21, 22.) Northern 

 Calitornia, rather rare. [M.] 



Valve linear-rhombic or rhombic, strongly gibbous in the 



Ann. d: Mag. S. Hist. Ser. 7. I y/. vii. 35 



