27S SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



acters are known, the outward taper of the rays indicates relations 

 with V. rodicifoniiis, while in the number of its rays, in the central 

 depression, and in its general expression it seems to agree better with 

 our V. f multiradiata. 



Occurrence. — Lower Carboniferous of Scotland. 



Genus Heteronema new genus 



? 1892. Vinella (part) Vine, Proc. Yorkshire Geol. and Polyt. Soc, 

 XII, pp. 84, 85. 



Zoaria, so far as known, consisting of usually simple, or locally 

 jointed, delicate, sparsely ramifying, tubular, creeping threads, ar- 

 ranged without apparent order. Pores rarely observed, apparently 

 always in a single row. 



Genotype. — H. capillare new species. 



This, the most simple type of the family, has been confounded with, 

 Vinella, but we believe it necessary to distinguish it because of its 

 extremely simple structure, and particularly on account of the absence 

 of the highly characteristic nuclei, and consequent radial arrange- 

 ment of the threads of Vinella. Regarding these nuclei as an essen- 

 tial feature of Vinella, we are enabled to present a more satisfactory 

 and clearer definition of the genus than would be possible if species 

 were included in which they are absent. 



We have so far observed only three species of this type, and one 

 of them is doubtful. The doubtful species is from Ordovician rocks, 

 the genotype seems to be a common fossil in the Silurian of Gotland", 

 and the third species a rare one in the basal part of the Coal Measures 

 of Illinois. It is scarcely to be doubted that other forms will turn up 

 when collections from intervening rocks are thoroughly searched. 



HETERONEMA CAPILLARE new species 

 (Plate LXV, ii) 

 Compare Vinella rcpens var. contorta Vine, Proc. Yorkshire Geol. and 

 Polyt. Soc., XII, 1892, p. 85, pi. Ill, figs. 5-7. 



Irregularly meandering threads, growing over shells and corals, 

 sometimes scattering, at other times growing so abundantly that the 

 crossing of the threads produces an irregular network. Threads 

 tubular, slightly compressed, of uniform size, 0.035 nim. to 0.04 mm. 

 thick, locally jointed. Pores not observed. 



This form is readily distinguished from associated remains of 

 Ctenostomatous Bryozoa by its delicate, irregularly intertwining, 

 simple, creeping threads, which form colonies varying from a few 

 scattering threads to patches an inch in diameter. It is possible that 



