Are a large group of closely-reated small to medium sized snails, that usually live in the lower parts of trees and bushes. Where one snail is found, usually a few others live in close vecinity. This group is a real challenge in terms of identifying the about 150 species reported from the country. The names that I have used here are merely an attempt to tell them appart rather than an accurate science.

My ids are based on:

Breure ASH, Ablett JD (2014) Annotated type catalogue of the Bulimulidae (Mollusca, Gastropoda,Orthalicoidea) in the Natural History Museum, London. ZooKeys 392: 1–367. doi: 10.3897/zookeys.392.6328

In some cases I also consulted: www.femorale.com

Drymaeus auris Pfeiffer,1866

45.3-48.7mm. Santander, Colombia.

The shell to the left is slightly juvenile, the middle shell is fully adult, and the giant to the right already shows signs of being found dead, due to ventral erosion, which in fact reveals a vivid rose-lilac undertone.
I have been interested in Drymaeus for a long time now and can say these shells are a rarity, these are also quite large for the genus and display a fascinating deep violet aperture, and shades of purple-brown on warm gray base.
The better match I could find: Drymaeus auris (Pfeiffer, 1866) but perhaps a new species? 
Anyways, really nice to see the trio displayed in every angle.

Drymaeus blandi Pilsbry, 1898

37.9&37.3mm. Cundinamarca. Colombia.

This species seems to live colonialy in areas of low andean forests around Bogotá. The shells are usually found dead and deteriorated, so the two depicted shells are truly exceptional. This is one of several species usually lumped into Dryameus flexuosus.

Drymaeus cognatus Pilsbry, 1901

35.67 & 38.6mm. N. Meta. Colombia

These two shells come from a very old collection, and were identified as Drymaeus flexuosus. Found at the base of garden plants in the road to Bogotá. The shells are quite lightweight and display strong variation. Notice the columellar lobe formed in the aperture. 

Drymaeus convexus group

From left to right:

Group 1: 28.3-35.9mm: These come from a location to the South-West of Bogotá, they appear to live colonialy. They display a wide array of pastel colors, ranging from solid white, to ivory or shells with either yellow, pink or lilac flush; or a combination of these.

Group 2: 29.4-32.1mm: These occur together with shells from group 1, in my opinion form plicatoliratus da Costa, 1898.

Group 3: 33.24-41.14mm: These shells come from a different location, to the East of Bogotá. They look like Drymaeus phryne from Perú, but this is obviously not the case, because of geographic distance. Reference: lectotype NHMUK 1975192

Drymaeus convexus gem.jpg

Drymaeus convexus

Pfeiffer, 1855

33.1mm.Cundinamarca. Colombia.

Yet another specimen from the East Bogotá form. This is extremely fresh; displaying a dark reddish brown cutticle.

Drymaeus buckleyi.jpg

Drymaeus cf. buckleyi

Sowerby III, 1895

32.6mm.Cundinamarca. Colombia.

So far this is the only specimen I have seen of this intriguing, light, slender species. D. buckleyi is an ecuadorian species.

Drymaeus fallax chicoensis.jpg

Drymaeus fallax chicoensis

A.S.H. Breure, 1977

22.7mm.Cundinamarca. Colombia.

This species occurs only in a small area adjacent to Bogotá. It is awkwardly shaped and solid white, with vermilion apperture.

Drymaeus felix.jpg

Drymaeus felix

Pfeiffer, 1862

33.6mm.Cundinamarca. Colombia.

One of several similar species; This is readily distinguished by the presence of a solid white spiral belt. The species is very uncommon.

Drymaeus flavidus.jpg

Drymaeus cf. flavidus

Menke, 1829

24.4mm. Cundinamarca. Colombia.

Small yellowish species, some shells are solid , others lightly streaked in the spire.

Drymaeus geometricus gem.jpg

Drymaeus cf. geometricus Pfeiffer, 1846

29.4&28.5mm. Valle del Cauca. Colombia.

This species lives near cloud forests in the mountains of the Cauca Valley. The adult shells are usually patterned like the shell to the left. A low percentage are solid lilac like the right shell. These have usually been classified as two different species by shell dealers.

Drymaeus nigrofasciatus

Pfeiffer, 1846

22.4mm. Bogotá, Colombia.

A small, common species in the suburbs of the colombian capital.

Drymaeus flexuosus.jpg

Drymaeus flexuosus

Pfeiffer, 1853

36.2mm. Tolima. Colombia. 

The real D. flexuosus: Largely restricted to Colombia´s central mountain range. This species´ name is almost always misused.

Drymaeus sykesi.jpg

Drymaeus cf. sykesi

da Costa, 1906

56.2mm. Cundinamarca. Colombia. 

This is by far the largest colombian Drymaeus I have seen; and oddly I still cannot figure a convincing id:  D. sykesi matches in size and locality only, the pattern and shape are somewhat different.

Drymaeus spadiceus gem.jpg

Drymaeus spadiceus

da Costa, 1906

36.2mm. Santander. Colombia. 

An extremely beautiful and rare Drymaeus, with a very large, flared aperture, and a very fine netted pattern.

Drymaeus tenuilabris.jpg

Drymaeus tenuilabris

Pfeiffer, 1866

30.8mm. Cundinamarca. Colombia.

Shells can be patterned such as this one or solid white. Rarely with full lip such as this.

Drymaeus violaceus superb.jpg

Drymaeus cf. violaceus Mousson, 1873

38.3 & 38.9mm. Valle del Cauca. Colombia

This large and handsome species shares habitat with D. cf. geometricus. In contrast to the former species, the shell is much more lightweight and translucid. Not sure of id; D. baranguillanus, D. solidus, D. confluens seem plausible ids.

Drymaeus ziczac.jpg

Drymaeus cf. ziczac

da Costa, 1898

27.8mm. Cundinamarca. Colombia.

Small species known only from a tiny creek. Dubious id.