Diatoms from Peruvian Guano. By Bev. Leivis G. Mills. 867 



The form to which it bears the closest resemblance is, I think, 

 Auliscus racemosus Greville,* yet the differences of markings and 

 general character are far greater than those required to mark a 

 distinct species, and are quite sufficient, in my opinion, to give this 

 diatom a name and a place among the fossil forms of guano. (See 



The following is a description of the species : — 



Valve circular, moderately large; two processes, each sur- 

 rounded by a cluster of well-defined granules; umbilicus faint, 

 with faintly radiating, curved, and partly granulated lines from 

 umbilicus towards the processes. 



I would name it Auliscus constellatus nov. sp. Per. guano. 



Single examples of other forms, some rare and others common, 

 may sometimes be found, but as these are to be obtained from other 

 deposits to which they more steadily belong, and as their recurrence 

 may not be confidently expected, they cannot be tabulated with 

 the usual diatoms of Peruvian guano. 



* ' Trans. Micr. Soc. Lond.,' xi. (1863) p. 46. 



EXPLANATION OF PLATE XI. 



Fig. 1. — Aulacodiscus Kittoni var. X 320. 

 „ 2. — Auliscus constellatus n. sp. X 320. 

 „ 3. — „ ,, large specimen, x 320. 



3 M 2 



