What's the difference between conch and conchiform?

Conch

Definition:

(n.) A name applied to various marine univalve shells; esp. to those of the genus Strombus, which are of large size. S. gigas is the large pink West Indian conch. The large king, queen, and cameo conchs are of the genus Cassis. See Cameo.
(n.) In works of art, the shell used by Tritons as a trumpet.
(n.) One of the white natives of the Bahama Islands or one of their descendants in the Florida Keys; -- so called from the commonness of the conch there, or because they use it for food.
(n.) See Concha, n.
(n.) The external ear. See Concha, n., 2.

Example Sentences:

(1) Maggie Kelly, from the residents campaign group Communities Opposed to New Coal at Hunterston (CONCH), said: "The proposed power station would have a devastating impact on our community, damaging our health, our livelihoods and destroying the local environment.
(2) While their double-shelled relations (clams, mussels, oysters, scallops, etc) specialise in filtering water to remove food particles, and their single-shelled little cousins (periwinkles, whelks, limpets, conches) specialise in, well, adorning a seafood platter, cephalopods (octopus, cuttlefish and squid) specialise in a seriously impressive form of self-defence.
(3) The site is on the edge of the island, by the lighthouse, and opens directly on to La Conche beach and a wild stretch of coast.
(4) Consumption of carrucho (conch) salad was significantly associated with illness (P = 0.013, Fisher's exact test).
(5) Kitsch beachcomber paintings adorn the walls; bartenders in Hawaiian shirts serve cocktails in conch shells.
(6) The morphology of human ear conch is said to be rather individual, but a perfect person-identification by this mean is not possible.
(7) Photopigments in the conch retina were examined with special attention given to the photic vesicles characteristic of gastropod photoreceptors.
(8) During an exposure the subjects with atherosclerotic cardiosclerosis showed a higher pressure in vessels of ear conch than the healthy subjects.
(9) It is demonstrated by photographs-made in a 15 years' interval-that ear conch and auricular area can be typically marked by proceeding age and specific diseases.
(10) In order to correct dislocation and hypertrophy of the conch, if present, a posterior retroauricular approach is employed.
(11) I would particularly recommend Akata Witch by Okorafor, a quest fantasy set in urban Nigeria, drawing on Igbo beliefs, and Divrakuni's The Conch Bearer and sequels, set in India.
(12) The conch is reduced as much as necessary, the ear brought closer to the mastoid and held in place with sutures knotted on oiled gauze inside the conch.
(13) The original source of contamination of the conch salad was not identified.
(14) Faces were made out of shells on the front of jackets and the back of dresses, so that the clothes came to life as they walked the catwalk, giant plastic eyelashes fluttering above conch-shell pupils.