REPORT ON TEE DIATOMACE^E. 89 



nevertheless be viewed as of specific value, is the gradual diminution in size which the 

 cellules undergo as they approach the margin. 



Lauderia, Cleve. 



Professor P. T. Cleve, in his Examination of Diatoms found on the Surface of the 

 Sea of Java, 1 established this genus in honour of Mr Lauder, who has contributed so much 

 to our knowledge of the genus Cliwtoceros, giving the following definition : — " Frustules 

 cylindrical, side view orbicular ; covered, at least near the margin, with numerous short 

 hair-like processes or spines ; front view annulated. Sculpture consists of very fine 

 puncta." 



The Lauderise are very well marked, and cannot readily be confounded with any other 

 genus ; it is, therefore, not easy to understand the grounds on which Professor H. L. 

 Smith " failed to mention the genus in his Synopsis of the Families and Genera of Diatoms. 



Lauderia annulata, Cleve. (Plate VIII. fig. 7.) 



We have here represented an organism, found in a surface gathering made in the 

 Antarctic Ocean, which is obviously identical with the Lauderia annulata of Cleve. 3 

 It need not therefore be further alluded to. 



Lauderia elongata, n. sp. (Plate IX. fig. 4.) 



Forma cylindrica, annulata, quatuor vicibus longior quam latior, per superficiem valde 

 convexam terminata ; frustula in seriem per apicum coronam coherent. In mari Philip- 

 pin arum. 



This organism was found in a surface gathering made in the neighbourhood of the 

 Philippine Islands. It differs from Lauderia annulata, Cleve, in the following note- 

 worthy points : (1.) It is four times as long as broad, while in the latter the length 

 is equal to the breadth ; (2.) its surfaces of junction are almost hemispherical, while in 

 the latter they are hardly convex ; and (3.) it presents a line of junction around the middle 

 of the annulated connecting zone — a feature which is not indicated in the figure of 

 Lauderia annulata given by Cleve. 



That these distinctions must be regarded as of specific importance is at once obvious. 



Lauderia pumila, n. sp. (Plate IX. fig. 8.) 



Frustula annulata cylindrica triplo longiora, punctulorum corona marginak' seriatim 

 disposita. Ad insulas Philippinas. 



The four small cylindrical frustules here represented are annulate, and are in this 

 respect similar to the species last described. In the present case, however, the contiguous 



1 Bihang k: Svensk. Vet. AJcad. HandL, Band I. No. 11, Stockholm, 1873. 

 " The Lens., vol. i., 1872. » p. cit. f p. 8, pi. i. fig. 7. 



(bot. chall. exp. — part iv. — 1886.) D 12 



