228 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



■■ vest 



Fig. 88. — Family Bicellariellidae Levinsen, 1909 



A-L. Bicellariella ciliata Linnaeus, 1758. A. Larva viewed in profile, X100. 

 The terminal bud is inclosed in a kind of sheath. B. Aboral side of larva, X 62.5. 

 C. Oral side, X62.5; (A-C, after Barrois, 1877); ce, obscure portion of the body 

 cavity comprised between the two branches of the stomach; fl., flagellum; mi., 

 aboral mesoderm; -ph., pharynx; o, mouth of larva; C. D., digestive cavity; 

 PL, vibratile plume; Vt., terminal bud; op., large elements. D, E. Larva 

 viewed in profile and from the oral side; a, evaginated process; b, mouth; 



c, flagellum; d, rosette figure; e, color spot. F, G, H, I. Different stages of 

 an ovicell; (D-I, after Nitzche, 1876); m, border of mouth area; a, fertilized 

 edge; b, spoon-shaped or dome-shaped cyst; c, rounded fL-sure (covering cyst); 



d, muscle fibers within the latter. J. Two eggs with their enveloping membrane. 

 K. Ovicell" with the embryo. L. An erect zooecium showing some anatomical 

 details and the tentacular sheath. (K, L. after Smitt, 1868.) 



M. Cornucopina grandis Busk, var. producta MacGillivray. Anatomical 

 details showing the frontal membrane (fm) into which a single pair of parietal 

 muscles (p. m.) arc inserted; the plate (crypt) is probably a cryptocyst. The 

 zooecium has given rise by budding to two younger zooecia (z') and is connected 

 with its lateral neighbors by the communication pore (c. p.). Each of the three 

 communication pores (scptulae) is surrounded by a strong calcareous ring; occl., 

 occlusor muscles; rm, large retractor muscle. (After llarmer, 1902.) 



