NoTT. — On N.Z. Composite Ascidians. 323 



whose products pass out by a long vas deferens, which first 

 coils spirally four times round the mass of sperm-bodies. Its 

 after-course is not clear as in the case of its generic relative. 



The supposed ovary, which is in this case almost uniformly 

 present, is identical in position (fig. 1, ovr.). But the gland 

 itself is elongated, presenting an upper hemispherical and 

 lower conical end (fig. 5, ovr.). The ova are in this species 

 also small and transparent. 



But other bodies which are undoubtedly ova are present 

 near the vesicles in some cases. These are of large size 

 (fig. 1, or.), being equal to the intestine, and exhibit a central 

 clearer germinal area, with a deeply-stained oval nucleus 

 (fig. 3, nc). These are probably the fully-developed ova of 

 which the transparent bodies noted above are the originals. 



One or two tailed larvae, with a single pigment- spot and 

 three adhering papillae, were met with. They occupy the 

 lower test-layer in all instances. 



Family DISTOMID^. 

 Genus Cystodytes, von Drasche. 

 Cystodytes aucklandicus, n. sp. Plate XXX. 



Numerous colonies of large extent were obtained in Sep- 

 tember. It is the most numerous species met with on the 

 reef. 



Corm is moderately thick, averaging 5mm., and seldom 

 less than 4nim. Its colour is light-brown, with darker dots 

 where the zooids are placed. The test is fleshy and trans- 

 parent, allowing the white capsules surrounding the abdomi- 

 nal regions of its tenants to be seen from the exterior. Over 

 the surface runs a network of slightly lighter lines. The 

 openings of the test, whether branchial or cloacal, are not 

 very distinct, and are exceedingly small. There is no trace of 

 regular systems, but not more than four or five zooids are 

 present in each. 



Great difficulty is experienced in staining. The best re- 

 sults are obtained from sections stained after cutting, and from 

 sections left unstained, as the staining fluid (picro-carmine) 

 does not readily penetrate the dense cartilaginous test. In 

 specimens stained entire, though allowed to remain forty-eight 

 hours in the fluid, the middle layer was only slightly tinted. 



The outer test-layer is free from bladder-cells, exhibiting a 

 structureless matrix, in which are numerous test-cells. This 

 layer is very thin, and gives place to what at first sight ap- 

 pears to be simply a mass of bladder-cells throughout. Care- 

 ful use of high powers, however, shows that this appearance 

 is due to the lower cells being visible in outhne through the 

 upper. Fig. 3 gives the appearance of the test with obj. C. A 

 test-matrix is present (t.m.), in which are scattered numerous 



