ZYGNEMACE^E. IGo 



GENUS 49. MESOCARPUS. Hass. (1845.) 



Spore sphserical or oval, between two cylindrical, straight or 

 slightly in-bent lateral cells. (a) Copulation ladder-like, 

 threads free, or with one end attached ; (b) copulation lateral 

 between two neighbouring cells of a thread, rarely ladder-like. 

 Sterile cells often with a knee-like bend, and intergrown at the 

 bend with similar cells of another thread. 



Including also the genera Pleurocarpus and Craterospermum of Braun. 



t Spore membrane scrobiculate or punctate. 



M. nummuloides, Hass. 



M. depressus, Hass. 

 tt Spore membrane smooth. 



M. parvnlus, Hass. 



M. recurvus, Hass. 



M. scalaris, Hass. 



Sub-gen. Pleurocarpus, Braun. 



M. pleurocarpus, De Bary. 



t Spore menibrane scrobiculate or punctate. 

 Mesocaxpus nummuloides. (Hass.) De Bary. 



Sterile cells 7-14 times as long as broad. Zygospore spheri- 

 cal, or broadly ovoid ; membrane brown, scrobiculate. 



SIZE. Cells -015mm. diam. Zygospore '044 X -034 mm. 



De Bary Conj p. 80, t. 8, f. 9, 10. Cleve Mon. Zyg. p. 

 30, t. 9, f. 4, 5. Hass. Alg. 169, t. 45, f. 1. Rabh. Alg. 

 Eur. iii. 257. 



Sphcero carpus nummuloides, Hass. Ann. Nat. Hist. xii. 187, 

 t. 7, f. 12. 



In ditches. Fruiting in September. 



Plate XLI. Jig. 3. a, sterile cells X 400 ; b, fertile cells, with zygo- 

 spores, X 400. 



XKesocarpus depressus. Hass. 



Sterile cells 7-12 times as long as broad. Zygospore ellipti- 

 cal, compressed ; membrane brown, punctate. 



SIZE. -007--015 mm. 



Hass. Alg. 168, t. 44, f. 1. Jenner Fl. Tunb. Wells 184. 



Sphcerocarpus depressus, Hass. Ann. Nat. Hist. xii. 186, t. 

 7, t. 11. 



var. B. ovalis. Rabh. Alg. Eur. in. 257. 



Mesocarpus ovalis, Hass. Alg. 169, t. 44, f. 2. 

 Sphcsrocarpus ovalis, Hass. Ann. Nat. Hist. xii. 189, t. 7, f. 

 15. 



In boggy waters. 



