Verri/l, Notes on Madiata. 583 



tubercles, seen in the latter; in tlie more numerous and regular, 

 crowded plates, which closely cover the actinal membrane ; and in the 

 form of the ovarial i)l:ites, whicli are more obtuse outwardly, and have 

 the large genital orifices at the edge, forming notch-like openings in 

 the margin, while in B. picta the plates are more pointed, at the outer 

 end, and the genital orifices are small, round, and distant fi'om the 

 margin. 



Boletia rosea a. Agassiz, 1863. 



Lytechhnis roseus VeiTill, these Trans., p. 302. 



A reexamination of this species, and comparison with B. pileolus, 

 the type of tlie genus, has convinced me that I was wrong in reler- 

 ring it to Lr/fechinus, and that it is a true Boletia. The deep actinal 

 cuts, the remarkably large pediccllariae, the few scattered plates of 

 the actinal membrane, and the thinness of the test are sufficient to 

 separate it from Tjyt echinus. 



B. depressa, as figured in Voy. Venus, PI. 3, figs. 1-1% is a similar 

 species, but differs in having pointed processes bordering the actinal 

 cuts, and in its larger and more numerous tubercles. 



Evechimis, gen- nov. 



Test thick, circular, thickly covered with tubercles of various sizes. 

 Spines rather short, tapering, very unequal. Ambulacral zones with 

 two principal rows of large tubercles ; poriferous zones not widened 

 below ; pores beneath, near the actinal areas, arranged in obliquely 

 transverse groups of three pairs, very soon becoming irregular, the 

 inner ones being separated from the others by a vertical row of tuber- 

 cles, so that throughout the greater part of the extent of the zones, 

 both above and below, the pores form an inner, nearly regular, verti- 

 cal row, and two irregularly alternating rows, of which the outer is 

 more regular than the median row ; in the latter the pores are arranged 

 in a more or less zigzag line. 



Actinal area small, with shallow cuts; the membrane is thin and 

 bears a few scattered, rounded, granulated plates ; the larger plates, 

 near the mouth, bear minute spines and very small oval pedicellaria?. 

 Anal area covered by an outer circle of 8 to 10, larger, often spine- 

 bearing plates, and an inner converging cluster of smaller plates. — 

 Type, Echinus chloroticus Yal. 



Trans. CoN'XECTicuT Acad., Vol. I, 69 March, 1871. 



