ACTINOIDA. 685 



how contrived to swallow a valve of the great scallop, Pecten 

 maximus, of the size of an ordinary saucer. The shell fixed 

 within the stomach, was so placed as to divide it completely 

 into two halves, so that the body stretched tensely over, had be- 

 come thin and flattened, like a pancake. All communication 

 between the inferior portion of the stomach and the mouth was 

 of course prevented, yet, instead of emaciating and dying of an 

 atrophy, the animal had availed itself of what undoubtedly had 

 been a very untoward accident, to increase its enjoyments and 

 its chance of double fare. A new mouth, furnished with two 

 rows of numerous tentacula, was opened upon what had been 

 the base, and led to the under stomach ; the individual had, in- 

 deed, become a sort of Siamese twin, but with greater intimacy 

 and extent in its unions." 



The SEA ANEMONE, Edwardsia veslita, (Lat clothed,) is one 

 of the last discovered species, named after a distinguished natu- 

 ralist. It forms for itself a shell or clothing, into which it can 

 retire at pleasure, or when in shallow water the tide recedes, 

 leaving it exposed to the air. (Plate II. fig, 3.) 



The genus Lucernaria, (Lat. the plant verbascum,') includes 

 animal flowers which are bell-shaped, free or fixed to sea-weeds 

 by a narrow disk or stalk, from which they expand to a broad, 

 eight-sided disk, in the center of which is a quadrangular mouth, 

 and at each angle a bundle of tentacula ; surrounding the mouth 

 are festoons of ovaries. The largest are about an inch in height. 

 They are of various colors, but usually pink. The species fig- 

 ured on the Chart is L. auricula, (Lat. the ear-lap.) 



The other genera of the sub-order noticed on the Chart are 

 nearly all coralligenous. The forms which the corals assume 

 are extremely various, such as those of trees, shrubs, leaves, 

 obelisks, domes, etc. Their substance consists principally of 

 carbonate of lime. The surface is usually "covered with radi- 

 ated cells, each of which marks the position of one of the polyps ; 

 and when alive, animals appear like plants on every part of the 

 Zoophyte." The frame work or skeleton is called Polyparium, 

 or Polypary, (Polyp-structure.) It should be remembered it is 

 made, not as the bee constructs its cell, but by secretions of the 

 animal tissues, increasing without the consciousness of the polyp, 

 in the same rrjanner as the bones and other structures in the 

 higher orders of animals. 



FAMILY ASTR-EID^. These Actinoids have the corolla calca- 

 reous with marginal tentacula, excavated cells, and circumscribed 

 stars. Of these are the Astraa ananas, PINE- APPLE CORAL, (see 

 Chart.) Prof. Dana says : " calculating the number of polyps 

 that are united in a single astrsea dome of twelve feet in diarn- 



