TUNICATA. 325 



Dorsal Tubercle simple, ovate, with the opening slightly on one side and the horns 

 turned in (fig. 36). 



Alimentary Canal forming an open loop ; intestine short and wide. 



Gonads flattened, ovate, hermaphrodite polycarps, placed on both sides of the 

 mantle, 10 on left side and 12 on right (fig. 37). The oviduct and vas deferens are 

 shown in fig. 38, and part of the testes in fig. 39. 



Locality : Station LIIL, 10 miles north of Cheval Paar, 9 fathoms, one specimen. 



Polycarpa palkensis, n. sp. Plate VI., figs. 5 to 8. 



External Appearance. An ovate sandy mass, attached by a large area to a dead 

 chank shell. Apertures inconspicuous, at opposite ends of the body. Size about 

 2 centims. in length by 1'5 centims. in breadth. 



Test stiff, entirely encrusted with sand to a thickness of about 5 millims. 



Mantle opaque. When the test is removed the body is of fusiform shape with the 

 two prominent siphons almost at opposite extremities and directed away from one 

 another (fig. 5). 



Branchial Sac with four folds on each side ; about six bars on each fold, and 

 three rows of meshes in the interspace. The transverse vessels are of two sizes 

 (fig. 7), the meshes are transversely elongated, with six or seven stigmata in each. 



Dorsal Lamina a very narrow plain membrane. 



Tentacles rather long, about 30, not all same length. 



Dorsal Tubercle rather large and complicated (fig. 6). The opening is anterior, 

 both horns are rolled inwards and one is much larger than the other. 



Alimentary Canal forming a small canary-yellow compact mass. 



Gonads, numerous elongate ovate polycarps (fig. 8), about 20 on each side. 



Locality : Trawled at Station XIX., in Palk Bay, 8 fathoms, one specimen. 



This species shows some resemblance to SLUITER'S Styela Jloccosa obtained by 

 the " Siboga," but differs in the gonads and other details of structure. 



Polycarpa colletti, n. sp. Plate VI., figs. 1 to 4. 



External Appearance. Shape erect, cylindrical, almost rod -like ; attached by the 

 posterior end with the branchial aperture on the anterior end and the atrial about 

 half-way down the dorsal edge (fig. 1). Surface finely creased or corrugated. Colour, 

 creamy white ; size, 2 '5 centims. x 8 millims. 



Test leathery. 



Mantle strong, opaque, yellow, closely adhering to the test. 



Branchial Sac with four low, rounded folds (fig. 3) on each side. Each fold has 14 

 or more closely placed bars, and there are two bars in the interspace separating a very 

 wide central row of meshes from two lateral narrower rows. The wider mesh contains 

 about eight stigmata and the narrower half that number. The transverse vessels are 



