100 PROCEEDINGS OF SOCIETIES. 
Dustin Microscorican Cuvus. 
25th June, 1874. 
Navicula gemmata, var. biseriata, Grunow= Navicula spiralis, 
O’Meara, exhibited—Rev. E. O’Meara exhibited some specimens 
of Navicula gemmata, var. biseriata, Grunow, mounted by our cor- 
responding member, F. Kitton, Esq., of Norwich. Mr. O’Meara 
considered the form identical with Navicula spiralis exhibited by 
him at the meeting of the Club in August, 1871, and so named by him. 
At this time he had not seen Grunow’s work, ‘ Reise der Novara,’ 
published 1868, and in which this form is deseribed ; if, indeed, the 
figures left any doubt on his mind as to its identity, the inspection 
of the example kindly supplied by Mr. Kitton had completely 
removed it. 
Section of Spine of Diadema setosum.—Mr. Mackintosh showed 
a section of the spine of Diadema setosum. These spines are long, 
hollow, and strongly serrated ; in section the central cavity is seen to 
be surrounded by a thin, dark-coloured ring, from which a series of 
slight solid pieces are given off, which, at first narrowing, after- 
wards expand into long isosceles-triangle-shaped segments, pale 
yellow in colour, and about equal in length to the diameter of the 
central space. The bases of these triangles are rounded, and form 
the longitudinal ribs, which project from the surface of the spines, 
and irregular bands of solid material pass from one ray to the other, 
sometimes exhibiting foramina. 
Human Hair presenting a remarkable alternate transverse dark 
and white Mottling.— Dr. Frazer exhibited a quantity of female hair 
of considerable length (upwards of thirteen inches), which was lately 
sent to a hairdresser in this city for manufacturing purposes, and 
found useless; it was reported to be “ Italian hair.” Every sepa- 
rate hair was finely marked with alternate white and dark brown 
colouring, so that, although the entire mass, at a short distance, 
was of a dark brown or brownish-black colour, a closer inspection 
showed that it presented the remarkable transverse mottling de- 
scribed. The white interspaces were very small, but occurred with 
strange uniformity along the entire length of the hair from end to 
end. As the mass had been cut off, it presented no roots, but the 
linear markings extended up to the point of removal. On measur- 
ing some of the coloured parts it was ascertained that a space of 4” 
covered five separate tints of hair—three white and two dark 
coloured. The tints shaded into each other if examined closely, but 
the change of hue, examined at a slight distance, appeared abrupt 
and complete. The hair was moderately coarse, but otherwise of 
good quality ; all its physical and microscopic characters were those 
of ordinary human hair. Of course, no history could be procured 
of the specimen, which, so far as Dr. Frazer’s information extended, 
was unique, approximating closely to the hair of some animals in 
coloration. 
