Vor. 2] Torrey.—Hydroids of the San Diego Region. Az 
Distribution. Pacific Beach, in the surf, attached in tufts to 
the posterior region of both valves of the beach clam Donaz, a 
most unusual situation for a hydroid, which may acount for the 
irregular, damaged margins of the hydrothecae. The beach was 
literally covered with the colonies, Jan. 2, 1904. Mouth of San 
Diego Bay, under similar circumstances, July, 1904. 
There is considerable variation in the length of the annulae 
or internodes on the stem and the annulation of the pedicels. 
Occasionally a pedicel has several annulae (fig. 9), but this is the 
ease only in the lower portion of the stem—e.g., the pedicel 
referred to is the lowest in the colony. More often the hydro- 
thecae are sessile; this condition is found in the distal portion 
of the colony. As a general rule, the annulation disapears from 
base to tip. 
The dimensions of the hydrothecae in four average specimens, 
are as follows, length first, in mm.: .69 x .45; .68 x .50; .50 x .52; 
A8 x .37. 
Dimensions of gonangia: .98 x .33; 1.14 x .28. 
This species is named in honor of that tireless friend of edu- 
cation and public spirited citizen of San Diego, Dr. Fred Baker. 
21. Clytia compressa (Clark). 
Campanularia compressa, Clark, 1876a, p. 214, pl. 8, figs. 5, 6. 
Clytia compressa, Nutting, 1901, p. 170, pl. 17, figs. 3, 4. 
Cytia compressa, Torrey, 1902, p. 58, pl. 6, fig. 49. 
Trophosome. As in C. everta. 
Gonosome. Gonangia compressed, broadly ovate, with truncated 
top and large aperture. 
Distribution. San Diego, 5 fathoms; San Pedro, Cal., 3 
fathoms. Orca, Al. (Nutting). Shumagin Is., Al., 6-20 fathoms, 
on Laminaria (Clark). 
Gonosome present, May 28 and July 13, 1901. 
