JOURNAL OF MICROSCOPICAL SCIENCE. 



DESCRIPTION OF PLATE VIL, 



Illustrating Mr. Brightwell's paper on Chaetoceros, and some 

 allied forms. 



Fig. 



1 and 2. — G. Bacillaria ? Bailey. 



3 to 7. — C. didymum, Ehr. 5*, side view. 



8. — O. gastridium, Ehr. 



9 to 11. — 0. incurvum, Bailey. 11, Dr. Bailey's figure reduced, equal 

 200 diam. 



12 to 15. — C. horeale, Bailey. 12 to 14 are copied from Dr. Bailey's 

 figures. 13, side view, red, equal 100. 15, from our own 

 specimens in all of which a slight constriction is visible 

 near the inner margin of the frustule ; the horns run straight 

 out at a right angle to the frustule. 



16 to 18. — C. Peruvianum (n. sp.). 



19 to 36. — C Wighamii (n. sp.) 19 to 27 represent varieties in form and 

 character of processes of the contained goniothecium-like 

 frustiiles, from widely distant localities. 29 and 30 show 

 the neck separating. 30, the cujj-shaped portion without 

 the neck, equal Omphalotheca liispida, Ehr. 32, side view. 

 33, a filament in its recent state drawn, in water with the 

 Endochrome. 34, short filament with internal frustules 

 irregularly placed. 35, side view of entire frustule. 36, 

 cingulum and horns without the frustule. 



37. — C. Mspidum, Ehr. 



38. — C. navicula, Ehr. 



39 to 42. — C.harhatum? 'Ehr. 



43 to 46. — Ooniothecium Bogersii, Ehr. 46, side view. 



47 and 4S.—G. Odontetta, Ehr, 



49 to 52. — Syndendrium diadema, Ehr. 52, side view. 



53 to 60. — Diocladia Capreohis in different stages of growth. 54, shows 

 the membrane, not unfrequently found adhering to the horns. 

 56, a side view. 58, frustules like this have probably given 

 origin to Ehrenberg's Ooniothecium didymum. 59, 60, 

 varieties. 



