On some new non-marine mollusks from Colombia and Peru

LIBRARY OF THE

UNIVERSITY OF ILLINOIS

AT URBANA-CHAMPAIGN

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v. 44
cop. 3

NATURAL HISTORY.
SURVFY

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FIELDIANA • ZOOLOGY

Published by
CHICAGO NATURAL HISTORY MUSEUM

3 Volume 44 March 21, 1966 No. 25

On Some New Non-Marine Mollusks from
Columbia and Peru

Fritz Haas

Curator Emeritus, Division of Lower Invertebrates

NEW COLOMBIAN NON-MARINE MOLLUSKS

During the past several years, Dr. Frederick J. Medem, Field
Associate in Zoology of Chicago Natural History Museum, has made
numerous collecting trips into different parts of Colombia. A by-
product of these journeys has been a rather large collection of non-
marine mollusks that is now under study by Dr. Alan Solem and
myself. Mostly these specimens provide range extensions for previ-
ously known taxa. Since completion of the larger review may be
considerably delayed, descriptions of the few novelties are presented
now. At the same time, the opportunity is taken to describe a re-
markable new genus of bulimulids from Peru.

Helicina (Oxyrhombus) unizonata, new species. Figure 48.

Diagnosis. — A relatively small species of the Helicina rhyncho-
stoma Pfeiffer, 1865, complex, characterized by its high, somewhat
convex spire, red spiral color band located two-thirds of the way from
suture to periphery, sculpture of weak spiral grooves, protruded pe-
riphery and nodular projection at the palatal-umbilical margin.

Several unbanded species: Helicina laus A. J. Wagner, 1905; H.
ucayalensis A. J. Wagner, 1910; and H. steindachneri A. J. Wagner,
1905; and one banded species: H. inca Preston, 1914, seem to be re-
lated, but present different combinations of sculpture, umbilical fea-
tures, shape and coloration. Helicina inca Preston, 1914, is larger,
much more depressed and lacks the basal nodular projection.

Description. — Shell turbinately conoid, of medium size, with
acutely angulated protruded periphery and 4% whorls. Spire strongly

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232 FIELDIANA: ZOOLOGY, VOLUME 44

elevated, sides slightly convex, individual whorls flatly rounded, H/D
ratio 0.730. Periphery protruding, white-edged, acutely angulated.
Sculpture of weak spiral grooves, rather widely spaced, crossed by
faint and irregular growth wrinkles. Color very pale yellow with a
single red spiral band, 0.65 mm. wide, behind the lip, located two-

Fig. 48. Helicina {Oxy rhombus) uni-
zonato, new species. Viewed from front.
X 3.

thirds of way between suture and periphery. Lip narrowly expanded
near suture, more so at periphery, rolled and thickened, but only
slightly expanded basally. Umbilical callus small, sharply outlined
on outer edge by a creased depression, but with smoothly extended
parietal callus area. Columellar margin deeply channeled, resulting
in a very prominent nodular expansion of the umbilical-palatal mar-
gin. Operculum still in shell, thin, without marked coloration.
Height of holotype 8.4 mm., diameter 11.5 mm.

Holotype. — Chicago Natural History Museum number 114098.
Region of Nueva Granada, Upper Rio Putumayo, downstream from
Puerto Asis, Putumayo, Colombia (76° 27' W, 0° 24' N).1 Collected
by J. M. Idrobo in July, 1957.

Remarks. — Much work remains to be done before we have a clear
idea of the relationships between members of the Helicina rhyncho-
stoma complex. At the present time species recognition is based on
combinations of characters related to size, shape, sculpture, color,
columellar and umbilical features. The specimen described here has
a combination of characters that are not duplicated by any previ-
ously described taxon and are very different from the characters
found in other species known from the Upper Amazonian basin.

1 Nueva Granada was a village of the Siona Indians, near Cuhimbe, Que-
brada Cuhimbe, west shore, Rio Putumayo, below Puerto Asis. In 1958 it was
abandoned and is not listed on any maps.

HAAS: NEW COLOMBIAN MOLLUSKS 233

Helicina decorosa A. J. Wagner, 1910, H. inca Preston, 1914 and
H. steindachneri A. J. Wagner, 1905, lack the nodular swelling at the
umbilical-palatal margin, as well as differing in size and shape. H.
ucayalensis A. J. Wagner, 1910, and H. laus A. J. Wagner, 1905, are
the only species from this region with the nodular extension, but have
quite different shapes and sculpture. The entire complex will be
discussed in a later study.

Fig. 49. Drymaeus gorgonensis, new species.
Viewed from front. X 2.

Drymaeus gorgonensis, new species. Figure 49.

Diagnosis. — An ovate-turrited, almost imperforate species of Dry-
maeus, with a slightly arcuate columella, unexpanded peristome and
smooth surface.

Drymaeus flavidus (Menke) from Venezuela to Panama is smaller
(height 19-22 mm.), has flatter whorls, distinct spiral sculpture, and
the columellar-parietal angle is much more obtuse. D. tenuilabris
(Pfeiffer) from Venezuela and Colombia is larger (height 30 mm.),
umbilicated, and has distinct spiral sculpture.

Description. — Shell rather thin, translucent, light yellow, almost
imperforate, ovate-turrited. Whorls Q}4, rather convex, separated
by a well-defined suture; surface almost smooth, showing irregular,
faint growth lines. Aperture less than half the height of the shell,
little oblique, narrowly elliptical, with simple peristome; columella

234

FIELDIANA: ZOOLOGY, VOLUME 44

Figs. 50-52. Solaropsis (Psadara)
undata, new species. Viewed from
above, front and below.

slightly arched, the columellar margin slightly dilated and almost
closing the umbilicus. Height 25 mm., width 11.1 mm.; height of
aperture 11 mm., width of aperture 4.1 mm.

Holotype. — Chicago Natural History Museum number 114164.
Island of Gorgona, Dept. Cauca, West coast of Colombia (78° 11' W,
3° N). Collected by Dr. F. Medem in February, 1961.

Remarks. — Only the single specimen was obtained. None of the
many West Colombian and Ecuadorian Drymaeus seem to be closely
related.

HAAS: NEW COLOMBIAN MOLLUSKS

235

Solaropsis (Psadara) undata, new species. Figures 50-53.

Diagnosis. — A species of the Psadara group characterized by a
slight keel at the periphery of the body whorl and by a surface sculp-
ture of slightly wavy, undulate rugae (fig. 53).

Fig. 53. Solaropsis (Psadara) undata, new species. Portion of shell surface. X 25.

Nearly all Solaropsis have a sculpture of fine to strong granula-
tions. The rugae of S. undata are unique. S. diplogonia (Dohrn)
described from Eastern Peru is similar in size, keeling and umbilicus,
but apparently has a simple granulose shell sculpture.

Description. — Shell thin, translucent, keeled at the periphery.
Spire depressed, suture well marked though not deep. Last whorl
slightly hollowed out above the keel, not descending in front; under-
side very convex, subcompressed around the deep, perforate umbili-

Figs. 54-55. Diplodon (Diplodon) losadae, new species. Viewed from outside
and back.

236

HAAS: NEW COLOMBIAN MOLLUSKS

237

Fig. 56. Diplodon (Diplodon) losadae, new species. Viewed from inside.

cus. Whorls 5%, regularly growing until the last one, which widens
rapidly in front. Surface of shell, except the umbilical region, cov-
ered with conspicuous, slightly wavy, undulate rugae which cross the
lines of growth. Upper margin of whorls regularly spotted at the
suture. Aperture shortly elliptical, almost circular, with a thin, dis-
junct peristome; lips not expanded or dilated except for a triangular
dilation of the columellar lip. Greater diameter 22.4 mm., smaller
diameter 19.5 mm., height 13.5 mm.

Holotype. — Chicago Natural History Museum number 114100.
North of coulee no. 3 of Rio Guayabero, in the direction of La Maca-
rena, Dept. Meta, Colombia {circa 74°W, 2° 30'S). Collected by
Dr. F. Medem in January, 1957.

Paratypes. — Chicago Natural History Museum number 95552.
Peru. From the Charles D. Nelson collection.

Remarks. — The two paratypes are slightly smaller than the type
and still immature. Although identified as S. diplogonia, the very

238 FIELDIANA: ZOOLOGY, VOLUME 44

distinctive sculpture shown by the shells was not mentioned in
Dohrn's excellent description and I consider them mis-identified.

Unfortunately, the type specimen was broken after the descrip-
tion and measurements had been completed, but the pieces are suffi-
cient to identify this species.

Diplodon (Diplodon) losadae, new species. Figures 54-56.

Diagnosis. — A decidedly rhombic species of the nominate sub-
genus with a marked posterior ridge.

Diplodon suavidicus (Lea) from the Amazon basin is very similar
in shape and has the same posterior ridge, but is only about 15 mm.
in length, while D. losadae is 47-48 mm. long.

Description. — Shell moderately solid, slightly inflated, inaequi-
lateral, shortly rhombic. Anterior end short, narrow, rounded; pos-
terior end broad, obliquely truncate. Anterior upper margin slightly
arched. Umbones low, not very full, their sculpture not visible.
Posterior slope high, separated from the disk by a marked ridge. Disk
rather smooth, showing many low and crowded growth lines. Hinge
normal, cardinals low, laterals thin and long, interval very short and
narrow. Dorsal outline convexly lanceolate, greatest thickness of
shell at about the middle. Mother-of-pearl bluish, somewhat irides-
cent. Length 48 mm., height 30 mm., diameter 17 mm.

Holotype. — Chicago Natural History Museum number 114042.
In the Cano Losada, Upper Rio Guayabero, Orinoco system, Dept.
Meta, Colombia (circa 74° 9' W, 2° 9' N). Collected by Georg Dahl
and Dr. F. Medem between March 1 and 15, 1959.

Paratypes. — Chicago Natural History Museum number 114043,
same locality as holotype; Chicago Natural History Museum num-
ber 114115, mouth of Cano Losada.

Remarks. — The six specimens are all 47-48 mm. long and show
no important variations. Apparently this is the first record of a
Diplodon from the Orinoco River system.

A New Bulimulid Snail from Peru

Among Peruvian land shells Chicago Natural History Museum
received from Mr. Abundio Sagastegui Alva of the University of
Trujillo in Peru, there was one lot which appeared to be as yet un-
described. Coincidence had willed that the identical species had
been received earlier from Dr. Weyrauch. These had remained un-
classified due to several strange features the shell offered that would

HAAS: NEW COLOMBIAN MOLLUSKS 239

not fit into the basic order of bulimulid shells as established by Pils-
bry. The two lots at hand came from different localities and are
composed of a sufficient number of specimens to rule out the possi-
bility that the characteristic shell features are due to individual or
local aberrations.

From its shell features it is very simple to describe this snail and
to give it a specific name. While in its external appearance it looks
very similar to certain species of Bulimulus or Drymaeus, it differs
basically in its apical structure. At first glance under a hand lens it
looks as if the apices were entirely smooth, under a magnification of
approximately 100 times, one sees on the first two whorls a series of
spiral lines caused by rows of very slightly impressed punctures, sim-
ilar, but not identical with the apical sculpture of the genus Macro-
dontes or the Brazilian genus Lopesianus Weyrauch. Of course, there
is no close relationship between these two and our Peruvian shell.

Kionoptyx,1 new genus

Description. — Shell having the aspect of a Bulimulus or a Dry-
maeus, but with an apical sculpture consisting of spiral lines formed
by little and rather superficial, punctiform impressions. Further-
more, the columella, at a little distance from the aperture, has a short
and ascending flange, quite different from the apertural teeth present
in some bulimulids.

Type species. — Kionoptyx sagasteguii, new species.

Kionoptyx sagasteguii, new species. Figure 57a, b.

Diagnosis. — A species of the above described genus Kionoptyx,
which, besides the features mentioned in the generic description, is
distinguished by its slender shell and the acute, hardly broadened
peristome.

Description. — Shell rather thin, translucent, slender, with 93^
whorls of regular growth which are hardly inflated and which give
the outline an almost straight appearance; the suture is very super-
ficial, getting a little bit deeper between the two last whorls. The
apex is slightly mammillar and has the sculpture described in the
diagnosis of the genus; its first half is slightly sunken. The outer sur-
face of the shell is smooth, lusterless, white with a few blackish-brown
streaks near the aperture. The umbilicus is reduced to a rim with
a blackish-brown, narrow band encircling it. The aperture is much

1 mm, kiovos, pillar, TTut, flange.

240 FIELDIANA : ZOOLOGY, VOLUME 44

higher than wide, with almost parallel columellar and palatal bor-
ders; the external dark streak near the aperture shines through.
Peristome acute, not broadened. Height 33 mm., width 9.75 mm.;
height of aperture 11.25 mm., width of aperture 4 mm.

Fig. 57. Kionoptyx sagasteguii, new species, a, Viewed from front, X 2.
b, Columella with flange, X 4.

Holotype. — Chicago Natural History Museum number 131682.
Marcabal, Prov. Huamachuco, Dept. La Libertad, Peru (77° 49' W,
7° 37' S). Collected by A. Sagastegui Alva on April 25, 1961.

Paratypes. — Chicago Natural History Museum number 131683
from the type locality (four specimens); Chicago Natural History
Museum number 131684 from the Hacienda Santa Elena, Rio Chus-
gon, 1,600 meters elevation, northeast of Huamachuco, Dept. La
Libertad, Peru (circa 77° 52' W, 7° 35' S), collected by W. Weyrauch
(18 specimens).

Remarks. — While the type is an adult specimen, it apparently was
collected dead and its surface is lusterless. Fresh examples, such as
the paratypes from the Hacienda Santa Elena, possess a certain shine.
The streaks, which in the type are restricted to the vicinity of the
aperture, can be present on almost the entire surface of the shell,
varying in color from light to dark brown. The degree of obesity
also varies somewhat, there being among the Santa Elena specimens

HAAS: NEW COLOMBIAN MOLLUSKS 241

one with the measurements 32 X 12.5 mm., which is almost devoid of
streaks and shows a dark one only in the aperture close to the peri-
stome, covering both the palatal and the columellar margin. This
peristome presents a minute suggestion of some broadening.

This novelty looks very much like Neopetraeus coerulescens var.
columna Pilsbry.1 The species coerulescens Pfeiffer is known only by
a verbal description and remains somewhat enigmatical; no descrip-
tion of the nepionic whorls was given and reference to the genus Neo-
petraeus Martens was tentative. Why Pilsbry attributed it to the
Neopetraeus is uncertain, since the general aspect of the shell is quite
different from that of the other Neopetraeus. In his description of
the new variety of Neopetraeus coerulescens, there is no mention of the
nepionic whorl sculpture. The only distinguishing feature of the new
variety is the sharp spiral fold on the columella deep within the aper-
ture, another feature not found in the genus Neopetraeus.

On the strength of the fact that the nepionic shell sculpture in
K. sagasteguii consists of rows of slightly impressed punctures and
not of "delicate sub vertical riblets, in the intervals between them
bearing closer, lower and finer spiral threads," as stated by Pilsbry
for Neopetraeus, I feel sure that Pilsbry's classification of Bulimus
coerulescens Pfeiffer and its variety columna Pilsbry is not correct.
To which bulimulid genus should this species and the one I am de-
scribing be attributed? Among the published genera or subgenera,
I don't know any that could come into consideration. Hence, there
is only one way out, namely, to create a new group — generic or sub-
generic — for the species involved, which is done here by calling it
Kionoptyx. Future studies will tell, once the anatomy is known, if
my creation can survive or not.

Again, now, to the above mentioned figures of K. coerulescens
columna: Its similarity to my new species is unmistakable, but there
are slight differences in shape and coloration which speak against
their identity. K. sagasteguii is more slender; the margins of the
aperture are more parallel, the aperture therefore narrower; the col-
umella is not black and the system of blackish-brown streaks on the
whorls is less dense and less regular. These conditions prompt me,
without ignoring a close relationship, to consider my shells as differ-
ent from both coerulescens and its variety columna, and to give it a
name of its own, that of its skilled and eager collector, Mr. Sagastegui
Alva of Trujillo, Peru.

> Manual of Conchology, 2nd ser., 11, p. 180, pi. 29, figs. 35-37 from "Peru."

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