Salpa. MOLLUSCA. MONOCHITONIDA. 471 



MONOCHITONIDA. 



Gen. CLIII. SALPA. — Branchial cavity open at both ends, 

 the orifice valvular. 



597. S. moniliformis. — Both extremities produced, the an- 

 teal one the longest, 



MacCullocTi's 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 August. 

 When young, the individuals adhere laterally in such a manner as to form 

 a chain upwards of a foot in length ; when fuU grown, and detached, they 

 exceed an mch 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. 



