REPORT ON THE TUNICATA. 69 



branchial aperture is placed on the dorsal edge, nearly 2 cm. from the anterior end of the 

 body. The atrial aperture is at the posterior end. The surface is covered with small 

 pointed tubercles placed mainly in longitudinal rows, of which there are six to eight on 

 each side. Towards the extremities of the body these rows become more distinct, and 

 at the posterior end they are raised up to form prominent toothed ridges. 



Length nearly 12 cm., breadth 3 to 3-5 cm. 



77ie Test is very transparent, and is thin and soft all over the body. Its thickiiess 

 between the toothed ridges is about 1 mm. 



Tlie Mantle has its musculature moderately developed. There arc ten transverse 

 muscle bands on the dorsal surface. Of these the second and third approach and join 

 one another dorsally, while the rest remain independent. All the muscle bands die 

 away on the ventral surface. 



The Endostyle is cons^^icuous on the ventral surface. It runs from the first to the 

 ninth muscle band. 



TJie Dorsal Lamina is large, but clear and transparent. The transverse ridges are 

 very slightly marked. 



The Dorsal Tubercle is large, but simple. It is elongated antero-posteriorly. 



The Visceral Mass is not large. It is placed near the posterior end of the botly, 

 between the ventral ends of the eighth and ninth muscle bauds. 



Locality.— ^OYCxahnx 6, 1875; South Pacific; at night; lat. 37' 50' 0" S., long. 93" 

 54' 0" W. ; surf. temp. 59° 7. 



The above description is taken from a single large specimen, somewhat injured, 

 which was collected near Station 295, in the South Pacific. The test is singularly soft 

 and flexible, so that it is impossible to say exactly what the shape of the body was when 

 living. A notable feature in the external appearance is the presence of the numerous 

 small papillae scattered all over the body. The toothed ridges which they form at the 

 posterior end of the body (PI. V. fig. 13) are about 2 mm. in height. Plate V. fig. 14 

 represents a section across part of the test and two of the ridges, natural size. 

 Between the ridges there are numerous irregularly scattered smaller papillte (PI. V. 

 fig. 13). The branchial aperture is a transverse curved slit, with slightly thickened lips 

 (PL V. fig. 15). The atrial aperture is torn in the present specimen. 



The musculature of the dorsal surface (PI. V. fig. 11) resembles somewhat that of 

 the solitary form of Salpa africana-maxima, where, however, there are only nine bands 

 altogether, and the second and third do not join as they do in this species. The 

 muscle bands run round the sides of the body, and end on the edges of the ventral 

 surface, so as to leave a space free from muscles on each side of the endostyle 

 (PI V. fig. 12). There are scattered muscle fibres on the tube-like posterior part of 

 the mantle which forms the atrial siphon. 



