CATALOGUE OF TUNICATA. 31 



Dorsal tubercle nearly globular, only attached by a short stalk at the 

 back. The free surface covered by a pair of closely-incurved spirals. 



Locality. Port Stephen ; one specimen, attached to Styela Wliite- 

 leggii, n. sp. 



In external appearance (PI. Cyn. IX., fig. 1) the most noteworthy 

 points are (1) the tangled mass of roots by which the specimen is 

 attached to the outside of the large Styela, and (2) the curious position 

 of the branchial aperture close to the point of attachment. The fact is 

 that the animal is attached by the ventral edge of its anterior end. The 

 relative positions of the apertures recall some species of Boltenia. The 

 test is of much the same colour inside as out. Its continuation into the 

 branchial siphon is provided with minute fusiform imbricating scales 

 (fig. 5, a, b, c). 



In the branchial sac the folds are rather wider than the interspace 

 (fig. 2), and have twice as many bars. The transverse vessels are in 

 some parts of three sizes, arranged with regularity, as shown in the figure. 

 Figure 4 shows the short dorsal languets, and fig. 3 the globular dorsal 

 tubercle. 



Cynthia cataphracta, n. sp,, PI. Cyn. XI., figs. 17. 



External appearance. Shape quadrate, compressed laterally, attached 

 by both posterior end and parts of the dorsal and ventral edges. Apertures 

 at the two ends of the wide anterior end, sessile, inconspicuous. Surface 

 even and moderately smooth, minutely granulated all over, with a few 

 long tag-like processes round the apertures and down the edges. Colour 

 of a pale creamy yellow. Length 3 cm., breadth 2'5 cm., thickness 

 l - 5 cm. 



Test very stiff and hard. The surface finely papillated all over, and 

 containing many large globular calcareous spicules, and also many 

 swollen ends of vessels. 



Mantle muscular. Sphincters very strong. 



Branchial sac with 6 folds on each side. The internal longitudinal 

 bars are narrow. There are 6 bars on a fold and three visible between. 

 The transverse vessels are of two sizes, generally 3 narrower between a 

 pair of wider. The meshes are large and about square, and are 

 generally crossed by a narrow horizontal bar. There are no horizontal 

 membranes on the transverse vessels. 



Dorsal lamina a series of languets. 



Tentacles 6 large and 6 small, branched. 



Dorsal tubercle cordate, turned with the opening to one side. 



locality.'- Attached to Styela per sonata, n. sp., from Port Jackson. 



