C. barquitensis Ritt. n.n. 
Plant no.36, map 5. KK 71.

Described by Backeberg as being similar to C. hypogaea, with tuberculate ribs, similar skin colour, clumping and areoles not so deeply set. 

Habitat
near Chañaral.

Ritter (1980) reduced this to synonymity under C. hypogaea.

C. boliviana Pfeiffer
 syn. C. echinoides (Lem) Br.&R.

Resurrected by Ritter in 1980, but the original description was vague, and Britton and Rose included this species under C. echinoides. Taylor (1981) has doubts about Ritter's conclusions in designating this as a valid species.

C. borealis Knize n.n. 
Plant no.4, map 3. KK 1396.

Here we have a problem with distance. These plants are considered by Knize to be C. echinata v. borealis Ritt. Perhaps it has links with the complex centred around El Cobre.

C. bridgesii (Pfeiffer 1847) Backeb. 
Plant no.30, map. 5. Ritt. 245. 

Body--elongated with ten broad and blunt ribs; Areoles-large, oval-shaped and close together; Spines-Radials 7, comb-like; Centrals 1, up to 3 cm long, some­times longer; Flower-small, inner petals sulphur yellow, outer greenish-yellow. Taylor (1981) doubts whether this species is distinct from C. marginata.

C. brunnescens Backeb.
(No latin diagnosis)

Body-broad, round, brown with ribs divided into irregular tubercles. Crown with freely produced wool. Spines-usually 6, spreading strong, tip dark to black, but golden at first, at base; Habitat-Chile