2 



WM. E. RITTER. 



General Characters. — Body cylindrical, slightly smaller at pos'erior 

 end ; uniformity of outline broken only by a median prominence on the 

 ventral side into which the digestive tract protrudes. Test thin and 

 transparent. Length of animal 7.5 cm. Both orifices strictly terminal ; 

 lips of branchial not prominent ; wall of atrial siphon thin, margin of 

 orifice divided into dorsal and ventral lobes by lateral notches. 



Musculature. — Body bands 16, rather strong, second to tenth 

 inclusive not interrupted at any point, first of series interrupted by a wide 

 interval dorsally ; eleventh to sixteenth inclusive interrupted ventrally. 

 General course of the bands parallel with one another, but second and 

 third inclined backward somewhat on dorsal side, so that these with fourth 

 nearly or quite in contact ; intermuscular bridges connecting the bands on 

 dorsal median line from about the fifth to the fourteenth ; sixteenth band 

 inclined forward on dorsal side. One continuous lip band, broader in 

 dorsal lip, narrower in ventral where it divides into two and makes a 

 sharp angle laterally. A pair of m ich smaller marginal bands in upper 

 lip. A pair of short longitudinal bands in dorsal lip extending from broad 

 lip-band nearly to dorsal terminations of first body bands; also a 

 longitudinal band at each angle of the branchial orifice extending back to 

 the second body band, and bending down into the ventr.il lip at its anterior 

 end. About twelve delicate bands in dorsal half of atrial sipho.i, the first 

 four or five larger; all but the first running together literally to make a 

 broader band on ventral side. About an equal number of siphonal 

 filaments in ventral half of siphon, the first broader and extending up on 

 to the dorsal surface. 



Branchial organs. — " Gill " of the usual salpa type, reaching from 

 the first body muscle to the thirteenth. Endostyle delicate, nearly straight, 

 extending back to the interval between the eleventh and twelveth body 

 bands. Hypophysis mouth forming a right angle, each arm of the angle 

 being about two mm. long ; dorsal tubercle not projecting greatly into the 

 pharyngeal cavity. Peripharyngeal band delicate. Ganglion and eye in 

 front of second body muscle from which the)' are about as distant as from 

 the hypophysis mouth. 



