192 Transactions. 



Liotia solitaria Suter to the Trochidae, as it is undoubtedly a juvenile 

 Turbinidae, belonging to the genus Astraea Bolten, 1798 — it being, in fact, 

 the juvenile of Astraea heliotropium (Martyn). 



In the Manual of the New Zealand Mollusca, 1914, Suter records Astraea 

 heliotropium (Martyn) as occurring from the Bay of Islands to Stewart 

 Island — that is, practically all round the New Zealand coast. It has been 

 obtained alive in Wellington Harbour, and is plentiful at Kapiti Island. 

 From a dredging off Cuvier Island in 38 fathoms I obtained two specimens, 

 of which Mr. Suter says, " No doubt the embryonic shells of Astraea 

 heliotropium (Martyn). Identical with my unfortunate Liotia solitaria.'''' 

 From near the Hen and Chicken Islands, in the Hauraki Gulf, in about 

 30 fathoms, a minute specimen, of 0-5 mm., without spines, was obtained, 

 which Mr. Hedley said was the embyro of an Astraea, and it is identical 

 with the protoconchs of the Cuvier Island specimens. Then, from off 

 Channel Island, in Hauraki Gulf, 26 fathoms, five specimens were obtained, 

 measuring 1-5 mm., 2 mm., 2-5 mm., 3 mm., and 4 mm. diameter — all 

 specifically identical with the Cuvier Island specimens. On the last spine 

 of the largest specimen the adult sculpture of Astraea heliotropium is just 

 beginning to show. Unfortunately, it is rather damaged and water-worn. 



A dredging off Chetwode Island, Cook Strait, 55 fathoms, gave two 

 young Astraea heliotropium (Martyn), of 18 mm. and 19 mm. diameter, so 

 far developed as to be quite unmistakable ; and two smaller ones, of 5 mm. 

 and 3-5 mm., the larger of which is much broken, though enough remains to 

 identify it with the larger ones, while it at the same time shows most 

 clearly its specific identity with the smallest, which is specifically identical 

 with the northern specimens. The smallest (3-5 mm.) has only three whorls, 

 and a wide umbilicus, within which all the whorls are clearly visible. The 

 upper surface is very slightly concave, the whorls coiled almost in one 

 plane ; colour white, the interior of the lip slightly nacreous. The largest 

 specimen has the protoconch sufficiently distinct to establish the specific 

 identity of the smallest. 



Mr. J. C. Andersen collected three young specimens of Astraea helio- 

 tropium (Martyn) on the beach of Kapiti Island — good examples, 30 mm., 

 34 mm., and 40 mm. In all three the protoconch is unusually clean, and 

 under a powerful pocket-lens the embryonic shell is clearly visible ; while 

 the largest one is particularly useful as exhibiting the gradual development 

 of the spines, the change from the depressed discoidal spire of the juvenile 

 to the somewhat raised spire of the adult, and the gradual increase of the 

 at-first nodulous spiral ribs, which when the shell reaches a diameter of 

 about 25 mm. change to close sharp growth lamellae on the spirals. These 

 three specimens are in the reference collection in the Dominion Museum, 

 Wellington. 



From dredgings in Dusky Sound I have a series of seven, of which four 

 are quite minute and the other three are unmistakable young Astraea 

 heliotropium (Martyn), 20 mm., 19 mm., and 13 mm. diameter, with clean 

 spires which show the embryos very well. This is perhaps the best locality 

 for this species. 



If all these specimens were mixed together it would be an absolute 

 impossibility to be sure of the locality of any single specimen. Specimens 

 illustrating this change from juvenile to adult have been placed in the 

 Dominion Museum. 



