12 MONOPHORA. 



The specimens collected at Juan Fernandez are all small, and are referred 

 with some doubt to this species. 



Juan Fernandez ; Cape Dos Baliias (East Coast of Patagonia). 



ENCOPE. (MoNOPiioRA.) 



Monophora Agass., 1847, in Des., Bull. Soc. Geol. Fr., IV. 287. 



A number of admirably preserved specimens of this genus have enabled 

 me to figure this interesting species, and to give some important details re- 

 garding its affinities, and the correlation of certain characters among Scutel- 

 lidae, which will be of considerable systematic value. 



The marginal limestone network connecting the actinal and abactinal 

 floors extends about half-way from the edge to the actinostome {PL III. 

 f. s) ; it resembles the marginal supports of Encope, showing no radiating 

 separations between the pillars, in the median ambulacral and interambu- 

 lacral spaces, as in Mellita ; this feature Mellita has in common with Echina- 

 rachnius. The walls separating the cavity of the jaws from the alimentary 

 canal are low ridges, corresponding in their course to the windings of the 

 analogous broad walls of Encope. The jaws, or rather the fragments which 

 were preserved, resembled the jaws of Encope ; the auricles are slender, elon- 

 gate. The marginal ambulacral indentations are reduced to mere re-entering 

 angular sides {PI. III./. 2), resembling the anterior ambulacral indentations 

 of some specimens of Encope Michelini {PL XII''. f. 4, Rev. Ech.). The am- 

 bulacral furrows are broad, shallow {PL Ill.f. l) ; the two main branches 

 diverge towards the edge, where they send off thin marginal shoots, rami- 

 fying but once or twice ; the main branches send off short, narrow, usually 

 simple branches. As in all Encopida; the median ambulacral and interambu- 

 lacral spaces on the actinal side are covered by elongate triangular bands of 

 large sunken tubercles, largest nearest the actinostome in the interambu- 

 lacra, and nearer the edge in the ambulacra ; Avhile on each side of the 

 ambulacral furrows the tuberculation is minute and uniform. Posterior inter- 

 ambulacral lunule with raised edges on the abactinal side. Tuberculation of 

 abactinal surface uniform. Five distant genital pores. Petals resembling 

 those of Mellita, uniformly petaloid, somewhat open at extremity. The 

 characters of this genus seem to show that Ave can consider Monoplioi-a only 

 a subgenus of Encope, as well as Ravenellia of Liitken (nou McCrady), which 



