Salpa. 
MOLLUSCA. MONOCHITONIDA. 
471 
MONOCHITONIDA. 
Gen. cl 1 1 1. SALPA. — Branchial cavity open at both ends, 
the orifice valvular. 
597. S. moniliformis . — Both extremities produced, the an- 
teal one the longest. 
MmCullocKs Description of the Western Isles, ii. 188. t. 29. f. 2. Flem. 
Edin. Phil. Journ. ix. 248. — Common in the sea among the Western 
Islands in i^gust. 
When young, the individuals adhere laterally in such a manner as to form 
a chain upwards of a foot in length ; when full grown, and detached, they 
exceed an inch in length. At each extremity of the back, there is a conical 
longitudinal process, nearly equal to the body in length ; the retral process 
exhibits some appearance of a vascular structure ; the stomach is of a dark 
brownish-orange, and (as well as the branchial band) is distinctly seen 
through the transparent gelatinous body. 
