THE NAUTILUS. 67 
As to P. stearnsii, if the shells sent to me by Mr. Stearns are con- 
specific with the type specimens named and figured (from his col- 
lection) by Mr. Pilsbry, then in my opinion stearnsii is only a 
young form of nigrisquamata and I suspect (from the description) 
that Patellu grata of Gould is the same shell. I am, therefore, in- 
clined to write: 
Helcioniscus nigrisquamatus Reeve (Patella), 1854. 
—=?P. mazatlandica Sowb., 1831. 
= P. grata Gould, 1859. 
= P. boninensis+-P. Stearnsii Pilsbry, 1891. 
Habitat: Japanese Seas, Stearns; ‘“ Australia,’ Reeve, error ; 
“ Chili,” Ruschenberger, ? error. 
PEROSTYLUS, THE EMBRYO OF MEGALATRACTUS. 
BY H. A. PILSBRY. 
In a former number of this journal (June, 1894) the writer 
proposed a new genus, Perosty/us, for the Cerithinm (Colina) bra- 
ziert Tryon and another supposed new species. Upon the appear- 
ance of the paper describing these forms, I was informed by my en- 
cyclopedie friend, Professor Theodore Gill that the type of the new 
group had been shown by Professor R. Tate to be the embryonic 
portion of “ Fusus” proboscidiferus. Some time after, the article by 
Tate, published in the Proc. Linnean Society of New South Waies 
(Australia), Second Series, Vol. VIII, pt. 2,’ p. 244, came to hand. 
In reference to Cerithium (Colina) Brazieri, Professor Tate writes : 
“The above named gastropodous shell is described in Tryon’s Manual 
of Conchology, Vol. LX, p. 142, and illustrated t. 26, fig. 16. The oc- 
currence of Colina in the Eocene beds of Victoria has led me toastudy 
of the recent species, and in doing so I was arrested by the unlike- 
1 Mr. Taylor is unquestionably right in considering Helcioniscus boninensis 
a synonym of nigrisquamatus Ry. I had satisfied myself of this by the exam- 
ination of the National Museum collection some years ago. He errs, how- 
ever, in placing H. stearnsii in the same category as it is a totally distinct 
thing. Mr. Taylor probably had the young H. nigrisquamata before him, as 
so acute an observer could hardly confuse stearnsii with the other species.— 
ED. 
? Issued March 12, 1894. 
