424 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loi 



somewhat branched folds. Parietobasilar muscles weak. Nemato- 

 cysts of the column 11.3-39.5 by 2.2-3.5 /x (basitrichs, probably 

 two kinds, the larger over 24 ix usually rare ; in a specimen from 

 Coronado Islands numerous) ; those of the tentacles 15.5-22.6 by 

 2.5-3 1.1 (basitrichs, common) ; those of the actinopharynx partly 

 12.7-26.8 by 2.2-3 jx (basitrichs, probably two kinds), partly 22.6- 

 28 by 4.2-5.6 jx (microbasic ^j-mastigophors) ; those of the fila- 

 ments partly 10-28.2 by 1.5-3.5 (basitrichs, probably two kinds), 

 partly 19.7-26.8 by 4.2-5 p, (microbasic 2>mastigophors). 



Color in alcohol : The tentacles and oral disc of a specimen from 

 Coronado Islands are green, two specimens from La Paz are brown, 

 a fourth almost uncolored. 



Cotypes. — Two specimens, U.S.N.M. No. 49459, east of La Paz, 

 March 21-22, 1940. 



Additional distribution records. — Coronado Islands, March 27, 

 1940, two specimens; Puerto Escondido, March 26, 1940, two 

 specimens. 



Remarks. — The pedal disc is well developed, but its diameter is 

 considerably shorter than that of the oral disc. The basitrichs 

 of the column are as closely set as the atrichs in the marginal 

 spherules. Possibly they are arranged in groups. Most of the 

 tentacles are so closely set at the margin that one could believe they 

 are arranged as those of the so-called stichodactyline species. How- 

 ever, this is not the case. Plate 14, figure 5, shows the exterior 

 of a specimen ; figure 79, d, the retractor of a directive mesentery. 

 The nematocysts have been examined in all specimens, and they 

 agree. In a specimen with more than 400 tentacles there are 192 

 mesenteries at the base. 



PHYLLACTIS CONCINNATA (Drayton) 



Figure 79, e-g; Plate 14, Figure 1 



Metridinvi concinnatum Drayton, m Dana, 1846, p. 152, pi. 5, figs. 40, 41. 

 Oulactis concinnata Milne-Edwards, 1857, p. 292. — Vekrill, 1869, p. 463. — 



Andres, 1883, p. 505.— Verrill, 1907, p. 268 (footnote). 

 Oulactis californica McMURRlCH, 1893, p. 196. 

 Asteractis concinnata Pax, 1912, p. 12. 



The pedal disc is well developed, the body usually strongly 

 contracted and then low (pi. 14, fig. 1). The upper part of the 

 column below the fronds is provided with 40 to 48 longitudinal 

 rows of verrucae to which sand may adhere. The fronds form a 

 ruff, each one bearing a variable number of papillae. The upper- 

 most fronds issuing from the first 12 endocoels project distally 

 over the others. The sphincter varies considerably. It is diffuse, 

 sometimes elongate, sometimes restricted ; rarely it shows a tend- 

 ency to be unilaterally circumscribed. In figure 79, e, 1 have drawn 



