308 
spines which are present in both distal segments of the rami of 
cirrus II, not only in the last segment, as in other species of the 
stellatus-g roup hitherto known. 
Chtamalus fissus Darwin. 
La Jolla, Calif. On the Coastal rocks. 21 /VIII 15. Numerous corroded 
specimens on Tetraclita squamosa , and Balanus glandula. 
La Jolla, Calif. The coast. 25/VIII 15. Numerous small specimens to- 
gether with Tetraclita squamosa. 
San Pedro, Calif. The coast. 27/IX 15. Numerous specimens together 
with Balanus tintinnabulum, and Tetraclita squamosa. 
Genus Chamæsipho Darwin. 
Chamæsipho columna (Spengler) Darwin. 
Mahia Peninsula, N. Z. On the coast. 18/XII 14. Severai specimens on 
Elminius plicatus. 
In his description Darwin (1853) especially calls the attention 
to the peculiar development of cirrus II and III of the present 
species; in cirrus II the anterior ramus is generally very much 
shorter than the posterior ramus, the segments of the first named 
moreover being bullate, and thickly clothed with spines. In cirrus 
III the anterior ramus exhibits a composite nature: the basal seg^ 
ments are bullate, and thick¬ 
ly set with spines, whereas 
the distal segments are siend¬ 
er, more cylindrical, with 
four or five pairs of spines 
along the anterior median 
line. In the present spec¬ 
imens (Fig.53 c) this struct- 
ure is strongly pronounced; 
in the cirrus the posterior 
ramus is very long, anten- 
niform, and only sparsely 
furnished with hairs. 
The mouth feet in 
structure very much ap- 
Fig. 53. Chamæsipho columna from Mahia Pen¬ 
insula. a mandible, b maxilla, c cirrus III. 
[a-b X 150, c X 48]. 
