PICTURESQUE SKETCHES 



rangement of their hard parts. They are called 

 Encrinites, or Crinoidal animals, because many of 

 them exhibit the appearance of a cup-shaped flower, 

 opening on the top of a stalk ; this flower-like shape 

 being comparatively simple in many species, while 

 in others there is a complication in the number of 

 branches stretching out from the principal stalk, and 

 in the multitude of arms and fingers projecting from 

 the aperture of the mouth, which seems quite unri- 

 valled in complexity in any other animal, whether 

 recent or extinct. 



A remarkable form of these crinoids existed during 

 Fig. 6 Fig. 7 the silurian period, and 



served, as it were, to 

 introduce these pretty 

 and curious examples 

 of organization. 



The figure (7) exhi- 

 bits the structure of the 



SILURIAN CRINOIDS. (Cystidea*) s t on y case in one Spe- 



cies ; and the annexed figure (6), shows the step by 

 which this ancient family, apparently the first in- 

 troduced, passed on to the higher organization of the 

 modern star- fish. The animal was without arms, and 

 was inclosed within stony plates, whose number was 

 sometimes indefinite, but an orifice was left in the 

 central part of the upper surface (m) for the mouth ; 

 an adjacent orifice (a) was provided, from which the 

 undigested parts of the food could be ejected ; and also 

 a third, at no great distance (o), for the expulsion of 

 the eggs. The mouth was provided with a proboscis, 

 moveable and covered with small plates ; while the 



* 6, Caryocrinus ornatus. 7, Caryocystites granatum. 



