270 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



As for the orientation of the external avicularium, in C. roydsi it 

 is horizontal or nearly so. In C. laytoni and C. margueritae it tends 

 to point a bit more obliquely upward from horizontal. In C. njego- 

 vanae it is much more oblique, pointing upward at a considerable 

 angle from horizontal. In C. rossi it points obliquely downward at 

 a very slight angle from the horizontal. In C. nutti it pomts downward 

 and forward at a very considerable angle from the horizontal. 



The normal number of external avicularia per zoid is two in C. 

 njegovanae and one in the other five new species, although occasional 

 zooecia do break the rule. , 



A very prominent peristomial cap or visor occurs in C. rossi. It 

 is absent in C. laytoni, C. margueritae, C. nutti, and C. roydsi. In 

 C. njegovanae the secondary orifice is formed by an extraordinary 

 downward growth of the frontal wall, reminding one of a face mask. 



The orientation of the frontal oral ledge is another important species 

 character. The oral ledge is parallel with the zooecial middle front 

 in C. njegovanae. In C. laytoni it is parallel with only one-half the 

 frontal and with one side, following the curve of the zooecial orifice. 

 In C. margueritae and C. nutti the ledge cuts across or encroaches upon 

 the proximal border of the primary orifice at a very slight angle. 

 The ledge cuts diagonally across the proximal border of the primary 

 orifice at a very considerable angle in C. rossi and C. roydsi. 



In general zoarial characters, i. e., gross appearance of the colony, 

 three distinct types are evident. One is the serrate cylinder or 

 column, as represented by C. laytoni; a second is the narrow, flattened, 

 tapelike colony as represented by C. margueritae and C. rossi; and a 

 third type is the heavy, bilaminate, flattened, flabellate or fan-shaped 

 slab as represented by C. njegovanae, C. roydsi, and C. watersi. Cel- 

 larinella nutti was intermediate between the slab and tape species. 



