BY C. HEDLEY. 189 



ACM.EA ALTICOSTATA, Allgas. 



From Port Lincoln, S.A., Angas described^' Patella alticostata. 

 He afterwards noted and briefly described t the same shell as 

 Patella costata, Sowerb}^ from Coogee and WoUongong, N.S. 

 Wales, But he failed to explain whether he had withdrawn or 

 only forgotten his own name. Boog Watson notes the species J 

 as P. alticostata, Angas, from Port Jackson, without allusion to 

 A. costata. Subsequent authors have united the names and 

 confounded the two species. The reference to Sowerby given 

 by Angas is incorrect, but it indicates '-^Lottia ? costata" 

 Sowerby,§ from " ? Coasts of Pacific Ocean." 



It does not seem to be generally known that there are two 

 species of Acmcea somewhat alike, the one inhabiting the Central 

 and South-Eastern Pacific, the other temperate Australia. The 

 Australian is larger, more solid, more elevated, with about 

 eighteen subequal ribs, the black border of the inside edge 

 usually continuous. From the Gambler Islands I have seen 

 examples agreeing with Sowerby's figure, in which the black 

 border is interrupted by the cords of the ribs; between the larger 

 ribs smaller ones are intercalated, and between the latter still 

 smaller ones. Patella stellcefonnis. Reeve, seems to me a variety 

 of A. costata, Sowerby. 



To clinch the argument that A. costata and A. alticostata are 

 different species, the former Pacific, the latter Australian, I 

 would remark that Capt. Beechey does not appear to have 

 touched during the voyage of the "Blossom" at places where 

 the latter species was procurable, but during his survey of the 

 Gambier Islands he would have had the opportunity of gathering 

 the former. 



Strebloceras cygnicollis, n.sp. 

 (Plate viii., figs. 12-U.) 



Shell minute, glassy, translucent. The apex lateral, of two 

 whorls in one plane; remainder describing half a revolution of a 



* Proc. Zool. Soc. 1865, p. 56, pl.ii., fig.l. 



tProc. Zool. Soc. 1867, p. 221. 



X Chall. Rep. xv. 1886, p. 26. 



§Zool. Beechey's Voy. 1839, p. 147, pl.xxxix., f.l. 



