468 W. C. Sturgis — Type- Specimens of Myxomycetes. 



Physarum in.equale, Pk., Rep. XXXI, p. 40, 1878. The differ- 

 ence of opinion expressed by Lister and Macbride regarding this 

 species rests merely on a question of nomenclature. That Physarum 

 incequale, Pk., and Didyminm lateritium, Berk. & Rav., are the same 

 thing, there is no room for doubt, since the fact of their identity is 

 proved by type-specimens. If one adopts the principle that a spe- 

 cific, sub-specific, or varietal name originally given remains unaf- 

 fected by any subsequent change in the generic name of the same 

 species, then the name Physarum lateritium (R. & R.), Rost., 

 stands, and P. incequale, Pk., becomes a synonym. If, on the other 

 hand, one prefers the principle that the first authentic specific name 

 published under the genus in which the species now stands, shall 

 take precedence, then the name Physarum inaiquale, Pk,, must be 

 accepted, since, although Rostafinski transferred the present species 

 to the genus Physarum, he made lateritium a varietal, not a specific 

 name, and the specific name incequale was the first authentic one 

 Avhich the species received after its transfer from the genus Didy- 

 miiim. 



The type-specimen is very scanty, but it shows the rather pecu- 

 liar characteristics of the species; the membranous sporangium-wall 

 with innate, pale yellow granules of lime and beset with reddish- 

 orange masses which give it a rugose appearance ; and the large, 

 rounded lime-knots of the capillitium, yellow, with reddish-orange 

 centres, and connected by extremely delicate threads. The reddish 

 masses seen on the surface of the sporangia and occupying the 

 center of the lime-knots are amorphous accretions consisting appar- 

 ently of plasmodic matter. Their appearance and structure are 

 quite different from those of the lime-granules proper. In the type- 

 specimen the latter ai*e always spherical, pale yellow, and exception- 

 ally large. The peculiar structure and double coloration of the lime- 

 knots is very apparent in the type-specimen (although here and 

 there one is seen which does not show the red center), and in all of 

 the specimens of this species which I have seen. The gi'eat varia- 

 tion in the size of the spores which led Peck to suppose that the 

 larger ones were ^'an investing membrane which encloses the true 

 spores," is evidently due to the immature condition of parts of the 

 specimen. 



Physarum pulcherripes, Pk., Rep. XXVI, p. 75, 1873. The 

 type-specimen is an exceptionally fine one. The following descrip- 

 tion is made from a portion of the specimen sent me by Professor 

 Peck. 



