228 Mr. S. I. Smith on a ncio Genus and 



5. Archagaricon conglomeratum. 



Tubes large, uneven, cramped, and warty, irregularly en- 

 larged and occasionally much constricted, anastomosing, and 

 studded with cells of various sizes, sometimes so numerous 

 that the tubes are much obscured, the whole mass ajjpearing 

 filled with them. 



Several specimens have occurred of this well-marked spe- 

 cies. The tubes are occasionally constricted to •jj^^fj-'inch in 

 diameter, and are sometimes enlarged to considerably more 

 than twice that size. They are of an irregular form. 



EXPLANATION OF PLATES IX. & X. 



Plate IX. 



Fig, 1. Lenticular form of Archagaricmi, 



Fig. 2. Oval form. 



Fig. 3. Irregular elongated form. 



Fig. 4. Pedunculate form. 



Fig. 5. Irregular form, Avitli minutely reticulated surface. 



Fig. 6. A portion of the surface, enlarged, to show the reticulations. 



Fig. 7. Transverse section of lenticular form, 



Plate X. 



Fig. 1. General view of a few of the tubes, much enlarged, of Archaga- 

 ricon hdbosmn : a, peripheral envelope or cuticle of the fungus ; 

 h, one of the large terminal vesicles ; c, tubular enlargement. 



Fig. 2. A portion of a tube of the same species, more highly magnified, 

 with a terminal vesicle, showing the double marginal line. 



Fig. 3. An enlarged portion of a tube, with bulbous swelling and papillose 

 walls. 



Fig. 4. The same, showing spore-like bodies within : a, spore-like bodies. 



Fig. 5. Terminal extremities of three tubes without enlargements, show- 

 ing double marginal line. 



XXVI. — Dcscrij^ttions of a new Genus and two new Species of 

 Scyllarida3 and a new Species of JEthva from North America. 

 By Sidney I. Smith*. 



EviBACUS, gen. nov. 



Carapax very broad ; lateral border expanded, incision at 

 the cervical suture closed, and the margin behind it not in- 

 cised, llostrum broader than long, very slightly bilobed. 

 Eyes situated midway between the rostrum and the outer 

 angle ; the orbits entire, slightly removed from the anterior 

 margin and connected Avith it only by a suture. Antennaj 

 with the inner margins approximate. 



* From Silliman's American .Tounial, .Tulv 1800. 



