108 ON THE FILAMENTOUS, LONG-HORNED DIATOMACEiE, 



In guano from Callao, occurring in small flakes or patches full of ])icces 

 of the horns, and a few detached frustules. Plate VIL, figs. 16 — 18. 



§§§ Horns proceeding from a cingulum or ring, dividing the frvstules, 



10. C. Wighamii, Brightwell. Frustules cup-shaped, with a band round 



the mouth of the cup, and a neck or bulb, proceedins^ 

 from the centre Frustules beset with minute short 

 spines, or pai)illa3, in all parts, except the band. Oval, 

 on a front, or end view, the spines appearing as minute 

 specks. Boiled in acid, the filaments break up, and 

 the frustules, in an isolated state, and detached rings, 

 with the horns proceeding from them, are all that can 

 be detected. The rings may readily be distinguished 

 from the frustules seen endwise, as they are open, and 

 without dots ; while the frustules, seen endwise, are 

 dotted. 

 In brackish water, near Breydou, Great Yarmouth. Plate VII., figs. 

 19—36. 



We have named this species after the discoverer, Mr. Wighani, an 

 excellent practical botanist, indefatigable in the piirsuit of his favourite 

 study, and most liberal in his communications to his friends. 



11. C. crenatum. i All these species are described or figured by Ehren- 



12. C. hispidutn. ( berg, from frustules found in a fossil, or deposit 



13. C. navicida. i state, and appear to belong to this section of the 



14. C. harbatum. J genus Chcetoceros* 



The 0. Wighamii was, as before stated, found near the salt-water 

 estuary, called Breydon, at the jioint where the rivers Yare and Waveney 

 meet. It occurred in a gathering made from a dirty ditch of brackish 

 water, at the back of a small public-house, called " The Buruey Arms," 

 which is marked on the Ordnance maps. The gathering abounded in 

 Gampylodiscus chjpeus (a s[)ecies chiefly known before as occurring in 

 fossil earth from Bohemia), and in one or more species of Mastugloia ; 

 it also contained Bacillaria p)aradoxa, Amphora sulina, Navicula palju- 

 hralis and tiimens, Mdosira varians and suhjiexilis, and the Ulva Indlosa (f); 

 and Protococcus hcematodes (?) abounded also in it, with which last the 

 Ohcetoceros seemed most associated. It was perhaps parasitical on some 

 Alga;, and, after being detached, had floated to where it was discovered. 

 This place has been frequently visited since Mr. Wighani's decease, and 

 searched in vain, for the Ohcetoceros ; although most of the above species 



* We subjoin a roference to the figures of most of the species above referred to, 

 given in the Plates to Ehrenberg's Microgeologie. 



