104 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



each raised on small, rough, sharply defined papilla) that are scattered 

 over the surface. Test tough, yellowish white, opaque, and moder- 

 ately thick in some places, but in the interior only thin laminae gen- 

 erally separate adjacent individuals. The surface, though with some 

 wrinkles, is in many places fairly smooth, but never shiny, and is 

 nearly free from incrusting materials. Size of entire cluster 28 mm. 

 by 21 mm. The individuals are of different sizes, the largest 17 mm. 

 long, but it is not unlikely that they are all somewhat immature. 

 The following details were made out in the larger individuals: 



Apertures widely separated. Mantle thin and delicate, its mus- 

 culature slight. 



Tentacles of 3 sizes quite regularly arranged; normal total number 

 probably 32. 



Dorsal tubercle oval, broader than long, with a transversely elong- 

 ate aperture which forms a complete oval except for a very small 

 open interval on the forward side. 



Dorsal lamina plain-edged. 



Pigs. 56, 57. — Polyandrocarpa maxima (Sluitkr). 56, Left and right sides of body 

 of zooid. X 1.5. 57, Gonad. Side next to branchial sac. X 36. 



Branchial sac with four well developed folds on each side, which 

 are separated by wide intervals. Transverse vessels of three orders 

 fairly regularly arranged, the smallest crossing the stigmata. In- 

 ternal longitudinal vessels distributed about as follows on the right 

 side of a large individual. 



dorsal 4 (13) 5 (16) 5 (16) 4 (11) 6 ventral. 



They are generally separated by from four to six stigmata on the 

 intervals between folds. 



Stomach short and rounded with a varying number (about 15 

 to 20) of longitudinal folds, but no caecum worthy of a name, though 

 a slight protuberance exists in its place. Intestinal loop forming a 

 more or less rounded curve of varying width, then bending abruptly 

 forward to the rather short rectum. Margin of anus two-lipped. 



Immature reproductive organs were found in two of the larger 

 individuals, and consisted of a few (not over five or six) oval or 

 flask-shaped gonads on the inner surface of the mantle on each side 

 of the body. They each contain an ovary in the part lying against 

 the branchial sac and a double row of testes in the part next to 

 the mantle, the sperm ducts embracing the ovary and uniting to 

 form a common duct which lies upon the free surface of the ovary 

 and ends on a papilla beside the ovarian opening in the usual manner. 



