Tag Archives: plekocheilus

New land snail from Venezuelan tepui

Venezuelan tepuis are a fascinating environment for land snails, and several new species have been described during recent years. Material from tepuis previously unexplored for their malacofauna comes in occasionally. Earlier this year Phillippe Kok (Free University, Brussels) showed some material from Angasima tepui, and one of the species appeared to be new to science.

Schermafbeelding_2012-12-26_om

This new species was named after its collector, Plekocheilus (P.) phillippei; the holotype is RBINS MT2576. The anatomy (genitalia, radula) is also described.
0schermafbeelding_2012-12-26_om

Reference:
Breure, A.S.H., 2012. Living in isolation: Plekocheilus (P.) philippei spec.nov. from Venezuelan Guayana (Gastropoda, Amphibulimidae). – Basteria 76: 101-106.

New paper

Today a new paper was published written together with Francisco Borrero (Borrero & Breure 2011). It revises the Amphibulimidae (genera Dryptus and Plekocheilus) from Colombia and adjacent areas.

Screen_shot_2011-10-10_at_13
The following new species are described, all from Colombia:

Plekocheilus (P.) bigener from Dept. Riseralda, Parque Nacional Natural Tatam??, Cerro Tatam??, 3600-3770 m (holotype RMNH 125626).

Screen_shot_2011-10-10_at_13

Plekocheilus (P.) incognitus from Dept. Antioquia, Medell??n, Vereda Piedras Blancas, 2200 m (holotype UAM).

0screen_shot_2011-10-10_at_13

Plekocheilus (Eurytus) camaritagua from Dept. Amazonas, Corregimiento La Pedrera (holotype ICNB).

1screen_shot_2011-10-10_at_13

Plekocheilus (Eurytus) paraguas from Dept. Valle del Cauca, Serran??a de Los Paraguas, Corregimiento El Boquer??n, Vereda Las Amarillas, near Cerro El Ingl??s, ~2160 m (holotype UVZ 97015).

2screen_shot_2011-10-10_at_13

Plekocheilus (Eurytus) labiosus from Dept. Cundinamarca, Parque Nacional Chingaza, Embalsa de Chuza, ~3100 m (holotype UVZ 97034).

3screen_shot_2011-10-10_at_13

All together 60 taxa are treated, with several keys to species (groups); additionally some taxa are reproted as unassignable or as erroneously reported from Colombia. Several species from neighbouring contries (Ecuador, Venezuela, Panama) are also included. 

Venezuelan Guayana Plekocheilus: SEM (1)

For a review of the malacofauna from the tepuis in Southern Venezuela and the adjacent area in Brazil, I recently made a series of Scanning Electron Microscope photographs. As not all pictures will make it to the publication – being slight variations on the same theme – I choose to make the photographs available here.

Today, pictures of Plekocheilus (Eurytus) huberi Breure, 2009 of respectively the mandibula, the central area of the radula, the marginal area and an overview to show the shape of the transverse rows.

110407pleko_3_2_huberi_mand

110407pleko_3_2_huberi_rad_c_l

110407pleko_3_2_huberi_rad_mar

110407pleko_3_2_huberi_rad_ovz

A type or not a type?

In their book on the molluscan names introduced by C.F. Ancey, Wood & Gallichan (2008)  gave many samples of handwritten labels by Ancey. The only label they held as an original Ancey type label that has been written on a type writer was Eurytus couturesi Ancey, 1900 (Wood & Gallichan, 2008: pl. 9 fig. x).

In the original publication Ancey states “I have seen two specimens precisely alike, differing only in size; the larger one, the type, is in my collection”. This specimen is now in the Cardiff museum (NMW 1955.158.24074); the location of the second specimen seen by Ancey remained unknown.

Recently, Francisco Borrero visited the museum in Ann Arbor and found a specimen of the same species, labelled a being from the “original lot”. It was part of the Bryant Walker collection before it reached the UMMZ collection.

When Francisco sent me these pictures, I decided to consult Jennifer Gallichan about the handwriting on the label. Was it really an Ancey label? 
Today she responded “after comparing it to labels and handwriting in our collection, we believe it to be a Fulton, not Ancey label. Fulton has a characteristic habit of underlining the author name and it was this that led to us to think that it is his writing. Unfortunately this does not help us determine once and for all if Ancey described this as a Colombian species. It is interesting that Fulton has noted ‘original lot’ on the label, which perhaps indicates that this is the other specimen which Ancey examined, however with no Ancey label present to confirm this, this can only be speculated upon”. 

There is a possible scenario in which Ancey based his description on material from Fulton, and purchased one specimen for his own collection; the second specimen could have been sold by Fulton. The mentioning of “original lot” supports this scenario. In this case the UMMZ specimen would be the paratype.
The other scenario would be that Fulton obtained a specimen after Ancey’s paper was published, recognized that it was the same species and identified it as such. The absence of an Ancey label supports this view. In this scenario the UMMZ specimen is without any status.
Thus the question remains: a type or not a type.

Note that the type locality “Bolivie” is supposed to be a place called Bolivia in Colombia (see my blogpost 14-06-2010 on www.ashbreure.nl). The label of the UMMZ specimen doesn’t resolve this issue.

Reference: 
Wood, H., Gallichan, J., 2008. The new molluscan names of C??sar-Marie-Felix Ancey including illustrated type material from the National Museum of Wales. BIOTIR Reports 3: i-vi, 1-162.

Image1Image2

Orthalicid radulae (11): Plekocheilus

Another species of this genus, Plekocheilus (Eudolichotis) aurissciuri (Guppy, 1866),  collected at Paramaribo, Suriname. From upper right clock-wise: half row (note that is probably a truncated radula), marginals 14-16, marginal 4, marginal 1, marginals 8-18, central and first eight lateromarginals.

Schermafbeelding_2011-03-17_om

The formula is C/1 + L 1/1 + M 15+x/2; x = 3, possibly more.

Orthalicid radulae (10): Plekocheilus

Some old pictures again today, this time of Plekocheilus (P.) aurissileni (Born, 1780). From upper left, clock-wise: central part of radula, overview of half a row, lateromarginals 10-13, idem 43-51, interaction between rows, lateromarginals 27-35.

Schermafbeelding_2011-03-14_om_18

 

The formula is C/1 + L 1/1 + M 50/2. The specimen was collected in the West Indies, St. Vincent.