394 Transactions. 



During the present year I received from Dr. Chilton two specimens of 

 Sternaspis scutata which were obtained during the cruise of the G.S.S. 

 " Hinemoa," off the Akitio Eiver, on the east coast of the North Island, 

 in from 20 to 36 fathoms ; and some years ago Mr. tSuter was good enough 

 to give me several specimens which he had obtained off Akaroa in 6 fathoms 

 of water.* These are, no doubt, the same species, though, as will be seen, 

 they differ a good deal in size ; and that they belong to the common species 

 from the European and American waters there can be as little doubt. 

 The Akitio specimens are the larger : one measures 15 mm. in length, with 

 a breadth near the hinder end (" abdominal breadth ") of 7 mm. ; the 

 breadth near the anterior end, in the region of the rows of chaetae, is 5 mm. 

 The worms are a good deal contracted, so that these measurements are 

 below those of the living individual. 



The characteristic posterior ventral " shield " is of very dark colour 

 — in one, a vandyke brown ; in the other, of a deep purple-brown. It 

 measures 5*5 mm. from side to side, with a length of 3-25 mm. at the 

 side, while tJie median line is 2-5 mm. This shield is fringed externally and 

 posteriorly by 15 or 16 bundles of long bristles ; it is difficult to make 

 out whether the former or latter number is correct, for at the hinder 

 corners the bundles are so close together that under a lens it is difficult 

 to distinguish them. The anterior rows of strong chaetae contain 11 in 

 each row. 



The specimens from Akaroa are much smaller : the largest is only 

 10 mm. in length by 4 mm. across the abdomen. The shield is brick-red, 

 is 4 mm. from side to side, and 2-25 mm. in length. 



The anterior rows contain 9 or 10 chaetae, the ventral ones being 

 slenderer and paler, indicating that they are young. There are 17 bundles 

 of bristles at the margin of the shield in one individual, and 15 in a second, 

 of the same dimensions. 



Both in the Akitio and Akaroa specimen, as in the Naples specimen, 

 the skin of the body is rough, being covered with groups of minute sand- 

 grains, which are visible only when a piece of the skin is mounted and 

 examined under a microscope. The fact that these grains are in groups 

 seems to indicate the presence of glands in the skin, to the secretion from 

 which the grains have adhered. 



I have, fortunately, some specimens of the European species, obtained 

 some years ago from tlie biological station at Naples (under the name 

 S. thalassemoides, which by most authorities is now replaced by Eanzani's 

 earlier name), so that I was able to make a comparison of the external 

 features between them and our New Zealand specimens. They vary in 

 size from 13 mm. to 21 mm. in length, with an abdominal breadth of 

 4-5 mm. to 9 mm., and anterior diameter of 4 mm. and 6 mm. respectively. 

 The dimensions of the shield vary in proportion. 



I wished to ascertain whether there are any points of specific difference 

 between this and the New Zealand specimens, but can find none. For 

 instance, not only does the size of the shield vary, as one would expect, 

 with the size of the animal — that is, with age — but the number of chaetae 

 in the anterior rows around the margin of the shield vary likewise. Thus 

 in the smaller specimens the rows of chaetae contain 9, in the larger 



* Mr. Suter wrote me that he had seat some of thess to Professor Elilers, of Got 

 tingen, who has, however, not published anything about them. 



