244 
ciful and elegant markings, Plate XIII. Fig. 60. Rosinus describes 
several varieties of this species of asterise, Tab. IV. et V. usque ad 
classum, M. In some of these species, the petal-like rays obtain 
somewhat of a curved form ; and in others, a flowret is disposed on the 
centre of the star already mentioned. With respect to their sides, 
they may be seen to tend in every degree to a pentagonal form. In 
some the circumference is formed by five slightly curved lines, united at 
angles hardly pei’ceptible. Fig. 6'1 ; whilst in others the curvatures 
become much greater. Fig. 62 ; and in some a considei’able indentation 
is formed on each of the five sides ; giving to the body an approach to 
the stellated form, as in Fig. 63 and 63, and increases in different 
specimens, as in Fig. 64 and 67 , until it is found to form the complete 
five-rayed star. Fig. 66. 
All these, as may be seen in the respective figures, differ again 
considerably, in the form of their rays, and the disposal of their 
markings. In one species. Fig. 68, these identations, on a margin 
approaching to the circular, are so sudden, and comparatively so deep, 
as to give a truncated appearance to the ends of the rays. The margin 
of this asteria is finely crenated, and being a little raised, the star is 
imbedded in a small concave depression. 
Bourguet describes a species which, instead of being marked with five 
petals, has five circular holes or cavities, at equal distances round the 
central foramen.* 
Rosinus, Hofer, Wolfart, and others, have spoken of asteriee with 
four sides and four rays. The only one of this kind which I have 
ever seen is depicted Fig. 59- Too little, however, is known respect- 
ing asteriae of this form, to enable us to determine whether this should 
be considered as marking a difference of species, or that of a variety 
only. The former supposition, however, appears to be the most pro- 
bable. 
• Traite des Petrifications, Tab. LVIII. No. 425. 
