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 Patella 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-j-P. Stearnsii Pilsbry, 1891. 
Habitat: Japanese Seas, Stearns; “Australia,” Reeve, error; 
“ Chili,” Ruschenberger, ? error. 1 
PEROSTYLUS, THE EMBRYO OF MEGALATRACTTJS. 
BY H. A. PILSBRY. 
In a former number of this journal (June, 1894) the writer 
proposed a new genus, Perostylus, for the Cerithium ( Co Una) bra- 
zieri Tryon and another supposed new species. Upon the appear¬ 
ance of the paper describing these forms, I was informed by my en¬ 
cyclopedic 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 ” probosddiferiis. Some time after, the article by 
Tate, published in the Proc. Linnean Society of New South Ayales 
(Australia), Second Series, Vol. VIII, pt. 2, 2 p. 244, came to hand. 
In reference to Cerithium ( Volina ) Brazieri , Professor Tate writes : 
“The above named gastropodous shell is described in Tryon’s Manual 
of Conchology,Vol. IX, p. 142, and illustrated t. 26, fig. 16. The oc¬ 
currence of Colina in the Eocene beds of Victoria has led me to a study 
of the recent species, and in doing so I was arrested by the unlike- 
1 Mr. Taylor is unquestionably right in considering Helcioniscus boninmsis 
a synonym of nigrisquamatus Rv. I had satisfied myself of this by the exam¬ 
ination of the National Museum collection some years ago. He errs, how¬ 
ever, in placing II. stearnsii in the same category as it is a totally distinct 
thing. Mr. Taylor probably had the young II. nigrisquamata before him, as 
so acute an observer could hardly confuse stearnsii with the other species.— 
Ed. 
2 Issued March 12, 1894. 
