THE NAUTILUS. 0 
though the siphon is not recurved; pillar smooth, nearly straight 
with little callus; the body with no subsutural callus; the outer lip 
slightly flaring, hardly thickened ; lon. of shell 26, of aperture 15.5, 
lat. 13.0 mm. 
San Pedro, Cal., in rather deep water, E. W. Roper; in whose 
honor the shell is named. 
This is a singular species, recalling Ocinebra or Muricidea by its 
surface sculpture and the constricted and appressed sutural region 
of the whorls. I have not been able to find any species with similar 
characters in the monographs or in the National Collection. It is 
probable that it should be separated sectionally from the group 
typified by F. colus, and it cannot be associated with Sipho or Chry- 
sodomus, so it may be regarded as typifying a new section, Roperia. 
NEW UNIONIDZ. 
BY BERLIN H. WRIGHT. 
U. Strodeanus sp. nov. 
Shell smooth, subtriangular, not inflated, inequilateral, rounded 
before, obtusely angular behind, slightly arched above and grace- 
fully rounded beneath. Substance of the shell solid and nearly 
uniform throughout. Beaks gracefully pointed, not prominent, 
scarcely extending above the short red ligament and surrounded by 
a few coarse, low undulations which do not extend back as much as 
usual. Umbos flattened. Epidermis olive-black, rayless. Not 
polished and with distant, faint marks of growth. Umbonial slope 
obtusely angular or rounded ; posterior slope slightly compressed 
and with two or three slightly impressed lines extending from beaks 
to margin. Cardinal teeth strong, deeply cleft and inclined to be 
direct. Lateral teeth prominent, curved and inclined to be double 
in both valves. Shell cavity moderate and quite uniform. Beak 
cavity slight and abruptly rounded. Cicatrices small, barely dis- 
tinct and well impressed. Nacre white and only slightly iridescent 
towards the margins. Width 2 in., length 14 in., diam. 3 in. 
Habitat: Escambia River, West Flordia. 
Type in National Museum. 
Remarks: Affinity, U. reclusus nobisand U. simulans Lea. From 
the former it differs in having a darker and rougher epidermis, not 
so pointed behind, flatter sides, shorter and teeth heavier. From 
