REPORT ON THE TUNICATA. 87 



Tlie Dorsal Lamina is represented by a scries of closely placed, large, tapering languets. 



The Tentacles arc large, and branched ; they are sixteen in number, placed long and 

 short alternately. 



The Dorsal Tubercleis large and distinct, elongated transversely but directed verti- 

 cally, the opening being on the right side ; both horns are coiled inwards. 



This species seems at first sight very like Savigny's Boltenia ovifera, but they differ 

 in many particulars. The resemblance is chiefly in the external appearance (PI. VII. 

 fig. 1), but the surface and colour are different, Boltenia ovifera being rougher and darker. 

 There is a species of Boltenia in the British Museum collection, unnamed but labelled 

 " from Australia," which is also very similar to Boltenia elegans, and may possibly be the 

 same species. 



The test is thin and allows the direction of the chief bundles of muscular fibres to be 

 seen through it in places. The muscle bands of the mantle are strong but do not form a 

 continuous layer. There are a number of distant parallel bands running down the long 

 axis of the body, and intersecting two series of bundles radiating from the apertures, so as 

 to form roughly quadrangular meshes (PI. VII. figs. 1 and 5, m. b.). 



The branchial sac is remarkable, and has eighteen folds, nine on each side. Those 

 next the endostyle are more closely placed and smaller than the dorsal ones. The trans- 

 verse vessels are wide and distant, and the narrow internal longitudinal bars run at right 

 angles to them so as to form the usual series of meshes (PI. VII. fig. 2, tr. and LI.). The 

 fine longitudinal or interstigmatic vessels, however, run transversely in place of antero- 

 posteriorly, and as a result the stigmata are directed transversely, and cross behind 

 the internal longitudinal bars in place of running parallel to them (PI. VII. fig. 2, I. v.). 

 The languets and tentacles show nothing noteworthy. 



The dorsal tubercle is large and has both horns coiled inwards (PI. VII. fig. 3, d. t.). 

 It lies in a moderately deep, triangular, unsymmetrically-shaped peritubercular area. 



The intestine lies upon the left side of the branchial sac, and is seen in Plate VII. 

 fig. 4. The oesophageal aperture (03. a.) is placed far back in the sac, and the canal lead- 

 ing from it — there is no distinct stomach — runs along the ventral edge of the left side 

 till it reaches the anterior end of the body, where it sweeps round dorsally, and makes 

 two or three zig-zags along the dorsal edge(t.), so as to reach the posterior end where the 

 anus (a.) is placed. This is a wide aperture with a beautifully fringed margin ; it is close 

 to the atrial aperture, and points posteriorly and dorsally. 



The genital masses are present on both sides (PI. VII. figs. 4 and 5) in the form 

 of elongated many lobed slightly branched organs directed antero-posteriorly, and termi- 

 nating close to the atrial aperture in a short genital duct (PI. VII. figs. 4 and 5, o. d.). 

 The left genital mass is rather the larger of the two, and lies chiefly in the intestiml 

 loop. 



