290 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iob 



Measurements: Minimum to maximum and average measure- 

 ments, in millimeters, are given below (for explanation see p. 271). 



Z-L, 0.778-1.080 (0.962) Se-Or-L, 0.127-0.158 (0.143) 



Z-W, 0.504-0.734 (0.638) Se -Oi-W, 0.144-0.173 (0.158) 



Av-L, 0.058-0.094 (0.074) Ly-L, 0.017-0.029 (0.024) 



Av-W, 0.043-0.058 (0.054) Ly-W, 0.086-0.101 (0.093) 



M-L, 0.029-0.050(0.040) Ov-L, 0.288-0.360 (0.318) 



M-W, 0.029-0.037 (0.035) Ov-W, 0.331-0.403 (0.360) 



Pr-Or-L, 0.101-0.130 (0.118) Op-L, 0.115 (Only one) 



Pr-Or-W, 0.171-0.187 (0.177) Op-W, 0.173 (Only one) 



I 



Zoarium: The encrusting zoarium grows over other Bryozoa. It is' 

 white, shiny, and rather smooth. The zooecia are large enough to se( 

 with the unaided eye. 



Zooecia: Large, longer than wide and mostly hexagonal, witl 

 walls more gently curved than angular. Zooecial boundaries ar(i 

 usually distinct. A slim, slightly raised mural rim is often presen 

 (pi. 25,D,E), but due to the convexity of the frontal surface these art 

 pushed down into the "valleys" at the sides of the zooecia so that the;* 

 are at a lower level than the rest of the frontal. The frontal is ; 

 fairly thick tremocyst, punctured by numerous medium-sized roundeo 

 pores placed relatively equidistant from each other. The fronta 

 between the pores is granular or beaded. The most elevated part i 

 the peristome, which is very similar in side view to that of Smittim 

 ordinata. 



The lateral and back walls are thinner than the frontal. Where 

 few zoids are free from the substratum the back walls appear gentl; 

 convex and entire. The lateral walls have five or six multiporou 

 pore plates in a line near the base. The distal walls also are porous 

 One zoid had three plates that were not as large as the side-wall pori 

 plates. 



Avicularium: No avicularia other than the oral ones are present 

 Every zoid has them, except the very youngest which have not ye 

 completed growth. 



The small elliptical avicularium is cradled in the depressed incom 

 plete part of the peristome. It is tipped forward and downward by 

 small curved ledge or hillock (pi. 25, K) so that it is situated roughly 

 45° angle away from the dorsal surface, along the longitudinal axis 

 The mandibular part is longer than the subhemispherical membranou 

 area. The mandible is tongue shaped, with parallel sides and a curve ' 

 tip. 



Orifice: The elevated orifice is nearly terminal. No oral spine 

 are in the present colonies. The secondary and primary orifices ar 

 different in shape. The former is somewhat like the sector of a circh 

 plate 25,B is most typical of it. It is less clithridiate than that of ^ 



