116 SYNOPTIC COLLECTION. 



builds up a large colony by a process of intermural bud- 

 ding. Fig. 2 shows how the buds are given off between 

 the walls of the coral lites, truncating three angles of the 

 parent form. Next, three more buds appear, truncating 

 the other three angles and pushing the original circle far- 

 ther away (fig. 3). Fig. 4 shows the circle of intermural 

 buds larger in size, while the buds between the walls of 

 the original circle (three of which are seen in fig. 3) 

 have been formed. These have increased in size in fig. 5. 

 In fig. 6 all these buds have grown and the corallites of the 

 original circle are separated not only from the parent form 

 but also from one another. Fig. 7 gives a vertical view of 

 the same, the numbers 1-6 corresponding with the numbers 

 of the views seen from above. These figures illustrate 

 finely how the shape of the corallites is due to pressure. 



Favosites (No. 160) is a compound colony like Miche- 

 linia. Its development follows the same general law that 

 governs the intermural budding of Michelinia, but is 

 more complicated, owing probably to acceleration in de- 

 velopment. Girty 1 has shown that the colony springs 

 from a single animal which is similar in general aspect to 

 the original zoon of Pleurodictyum. This zoon is pros- 

 trate, slightly curved at first, and is attached by its dorsal 

 side. When full grown the zoon is more erect and gives 

 off four buds from its dorsal side. Each is connected 

 with the parent form by means of a pore. Next, five buds 

 appear in the peripheral spaces between those already 

 existing. It is not until there are nineteen buds that the 

 original one is surrounded. In this one-sided or unilateral 

 budding Favosites differs from the last two colonies de- 

 scribed. 



The generalized members of the living Alcyonaria 

 the Proto-Alcvonaria are the three genera Monoxenia, 

 Hartea, and Haimea; of these, Monoxenia is represented 

 in the Collection by a drawing. It is unfortunate that 



l Amer. Geol., XV, Mar., 1895. 



