1892.] NATURAL SCIEKCE8 OF PHILADELPHIA. 329 



" I have made a careful comparison of the Sipho sent by you with 

 our series. 



" It difters notably from anything we have, and is probably, as you 

 suppose, an undescribed species, unless described as a fossil. We 

 have specimens of the ventricose varieties of S. Stiynpsoni, which 

 equal this in stoutness, and nearly equal it in curvature of the col- 

 umella, but the whorls are less ventricose, the shoulder less swollen, 

 the sutural region less deep, and the sculpture is very much finer." 



Comparisons have also been made by myself with the Atlantic 

 Siphos in the U. S. National Museum, and of course with the recent 

 and fossil series in the collection of the Academy. 



Diachcea Thomasii, a Neiv Species of Myxomycetes. — Dr. Geo. A. 

 Rex presented specimens of a species of Diachcea which he con- 

 sidered new^ and undescribed. 



This species was first found by Mr. Lancaster Thomas at Cran- 

 berry in the mountains of AVestern North Carolina, and later by the 

 speaker at Linville higher up in the same mountains. In both 

 cases the Diachcea was first found in the plasmodial stage. Owing 

 to the altitude of these places, 3,200 and 3,800 feet respectively, the 

 temperature even in July and August frequently falls at night nearly 

 or quite to the lowest point compatible with the life of the Plas- 

 modium or with its further development to maturity. By careful 

 protection, however, perfectly mature sporangia were developed. 



The sporangia are beautiful and conspicuous, hence the speaker 

 was inclined to believe the species local in its habitat, else it could 

 not have escaped attention up to this time in view of the increasing 

 interest taken by students in the study of these forms. The species 

 may be described as follows: 



DiACH.EA Thomasii n. sp. Plasmodium ochre yellow, immature 

 sporangia pure white, mature sporangia of a metallic lustre either 

 silvery or gold bronze partially iridescent ; growing either singly or 

 in clusters, stipitate or sessile, globose when stipitate but flattened 

 beneath when sessile; 2 to f of a mm. in diameter. Stipes variable, 

 usually short but sometimes equalling the diameter of the sporangium, 

 thick, rugose, dull ochre yellow in color, containing lime. Columellas 

 ochre yellow, rough, penetrating from i to * the height of the 

 sporangia, varying from bluntly conical to cylindric-clavate in 

 shape, containing minute round or oblong granules of lime. Spores 

 brown, 11-12 p- in diameter, with a peculiar warting, the entire 

 epispore, when examined by a medium power lens being sparsely 

 covered with minute papillae associated with from six to eight large 

 scattered warts or papillse apparently, which are resolved however 

 by a sufficiently high amplification into clumps of from five to eight 

 minute, closely aggregated papillje. 



Capillitium sparse, brown violet in color composed of rigid, straight, 

 tapering threads arising from the columella and base of the 

 sporangium, joined by a few lateral branches in the middle and near 



