Four different capillitial threads in Trichiida.

A. Capillitial threads of Trichia varia: isolated threads sculptured with spiral bands, two very short ones are indicated by a black line. B. Capillitial threads of Arcyria obvelata, forming a network and sculptured with spines. C. Capillitial threads of Oligonema flavidum, short and in this case branched, smooth. Note the reticulate ornamentation of the spores, similar to that of Oligonema schweinitzii and Trichia persimilis. D. Capillitial threads of Cornuvia serpula, branched and ornamented with rings. Scale and colours are approximate. Credit photos: Michel Poulain.