A. E. 'Verrill — N'orth American Ophiuroidea. 359 



Ophiohyrsella serpens (Lyman) is from the West Indies, in 69 

 fathoms. 



Another species, 0. Ays^nci's (Lyman), with five slender and rather 

 long spines, was dredged off the Shetland Islands, in 345 fathoms. 

 (Bulletin Mus. Comp. Zool., vol. x, p. 272, PI. viii, figs. 120-122, 

 1883.) 



Astrogeron Ver., gen. nov. Tj^pe, Ophiogeron supinus Lym. 



Disk and arms covered by a naked skin containing minute scales ; 

 beneath the skin are small rounded radial shields and very short 

 genital plates and scales. Teeth small, spiniform ; a cluster of spini- 

 form tooth-papillse at the end of the jaw, and a row of oral papillje 

 on the edge. Oral and adoral shields normal. No tentacle-scale. 

 About two slender, glassy arm-spines covered by skin. Arm-bones 

 divided longitudinally. The typical species of Ophiogeron has no 

 oral papillae, the jaw-plates being naked except for a few small spini- 

 form teeth at the tip, but, otherwise, it agrees pretty closely with 

 this. 



Astrogeron siqnnus (Lym.) is from the West Indies, in 200 to 

 464 fathoms.* 



Mr. Lyman has described several very remarkable genera, allied 

 in some respects to Op>hioscolecid€e^ but presenting such peculiar 

 structures that it does not seem reasonable to refer them to any of 

 the described families. They should be considered as types of two 

 distinct families, if the differences that separate families in other 

 cases are taken as our criteria. In fact, they present greater diver- 

 sities than can be found elsewhere in the entire group of regular 

 Ophiuroids. Therefore I i^ropose to classify them as follows : 



Ophiomycetidae, fam. nov. 



Snb-family, Ophiomycetince, nov. Type, Ophiomyces Lyman. 



Sub-family, OphiothoUnce, nov. Type, Ophiotholia Lyman. 



Ophiolielidse, fam. nov. Type, Ophiohelus Lyman. 



These groups Avill be described on subsequent pages. 



Family, OPHIOMYCETIDiE, nov. 



Disk swollen, covered with scales, which may be either naked or 

 spinulose. No radial shields. Teeth few. Two, three, or more 

 apical tooth-papillae. Oral papillae numerous, the outer ones large, 



* Bulletin Mus. Comp. Zool., vol. x, p. 270, PI. vii, figs. 103 to 106, 1883. 



