158 AMERICAN JOURNAL 



are about ten ; stomach small, intestine passing upward beyond 

 it on the right side three quarters of an inch before recurving. 

 Between the branchial sheet and the wall of the tunic are mul- 

 titudes of small round digit-shaped bodies attached to the tunic 

 by a slender pedicel of their external covering, often knobbed 

 or bifurcate at their inner end ; office unknown to me. Anal 

 orifice small, five lobed, three of the lobes quite prominent ; oral 

 orifice with a corrugated irregular comb-like crest above and 

 overhanging it and extending around it, apparently also five 

 lobed. Length three inches ; diameter at the distal extremity 

 •64, at about the middle, *25, at the attached extremity *13 in. 



Habitat. Monterey Bay, in 4 — 10 fathoms on shells, &c. Dall, 

 1866. 



This is a very peculiar species, probably not a Cynthia, but 

 I have not access at present to the works necessary to fully de- 

 termine its generic place. Other ascidians of several species 

 occur with it. It seems to be rather common, as my examples 

 were brought up on the anchor of a schooner upon which I went 

 to Monterey. 



SALPID^E. 



SAL PA, Forsk. 



Salpa herculea, n. s. 



Proles aggregata, ignota. 



Proles solitaria. Form approximating to cylindrical. Dorsal 

 surface studded with small conical elevations. Hrernal surface 

 smooth. Sides somewhat ribbed, smooth. Oral opening wide, 

 with thickened lips, not produced. Anal opening large, cylin- 

 drical, produced, with a circular aperture. Nucleus, or portion 

 enclosing the visceral tract, globular, very prominent, project- 

 ing below the general line of the haemal surface. Viscera 

 brown and scarlet. Muscular bands nearly or quite encircling 

 the body, corresponding to the ribbing of the sides, eleven 

 in number, connected in the middle lines of the sides by a 

 lateral band. Length eight inches. Diameter three or four 

 inches. 



Habitat. Near the Unirnak Pass, Aleutian Islands, in Lat. 

 41°, Lon. 144° 33', July 20, 1866. Dall, several specimens. 

 Coll. reg. No. 306. 



This magnificent Salpa, by far the largest of the genus, and 

 almost if not quite the largest single free tunicate known, is pro- 

 visionally described as above and will form the subject of a future 

 paper. Its size alone will distinguish it from any other species. 



