670 



CHORDATA 



in color with orange intestine: Bermuda; common along the shore and 

 on the reefs. 



FAMILY 3. POLYCLINIDAE. 



Colony variable in shape but usually massive, sometimes stalked, 

 and enclosed in a common tunic; individuals elongate, composed of 3 

 regions, sometimes in groups; incurrent opening 

 with 6 or 8 lobes ; budding by division of the post- 

 abdominal body region which contains the gonads, 

 the heart in the pericardium and the epicardium, 

 which is a tubular prolongation of the pharyngeal 

 sac (Fig. 1,014) : about 20 genera and over 150 

 species. 



AMAROUCITTM Milne-Edwards. Colony usually 

 massive, more or less gelatinous or cartilaginous 

 in consistency; individuals very much elongated 

 and usually in irregular groups: about 60 species, 

 most of which occur in shallow water. 



A. pellucidum (Leidy). Colonies large, com- 

 plex, consisting of many groups of elongate zooids, 

 each group having a common cloacal opening and 

 all enclosed in a common gelatinous, translucent 

 tunic; colony up to 15 cm. in diameter; separate 

 zooids up to 25 mm. long; stomach bright orange 

 in color: North Carolina to Vineyard Sound; very 

 common in shallow water. 



A. stellatum Verrill. Colonies large, often in 

 form of thick vertical plates which may be 60 cm. 

 long, 15 cm. high, and 25 mm. thick, enclosed by a 

 common gelatinous tunic, and called "sea pork" 

 by fishermen; color pale bluish or pinkish; zooids 

 arranged in stellate clusters containing from 6 to 

 20 individuals each; branchial sac and intestine 

 orange : very common from North Carolina to Cape 

 Cod and northwards. 

 A. constellatum Verr. Colony thick, often incrusting, with a smooth 

 surface, forming hemispherical crusts on piles, rocks, etc.; color orange 

 or pink; zooids arranged in irregular stellate or elliptical groups: Long 

 Island and Vineyard Sounds and northwards. 



FAMILY 4. DIDEMNIDAE. 



Colony incrusting, sometimes thick and massive, and contained in a 

 common tunic, in which are calcareous spicules; zooids arranged in com- 



"1 



Fig. 1,014 



Diagram of Amarou- 

 cium (Bronn). 18, tho- 

 rax ; 19, abdomen ; 20, 

 postabdomen ; 21, 

 blood space; 22, epi- 

 cardium, a prolonga- 

 tion of the pharyngeal 

 sac into the postabdo- 

 men. Other explana- 

 tions as in Fig. 998. 



