EXPLANATION OF PLATES. 145 



Fig. 1. Ophhtrema gracilis, upper face 



2. Opiuotrcma gracilis, under face. 



3. Ophiolrema albcrli, upper face. 



4. Ophiolrema albcrti, under face. 



5. Ophiomitrella porncla, upper face 

 G. Ophiomilrella porrecla, under face. 



Fig. 1 . Ophiacantha (Ophiotreta) affinis, under face. X4. 



2. Ophiacantha (Ophiolrcta) affinis, upper face. X4. 



3. Ophiacanlha {Ophwtrela) affinis, under face of another fspecimen. X5. 



4. Ophiomitrella Ixvipellis, upper face. X9. 



5. Ophiomilrella Ixvipellis, under face. X9. 



6. Ophiacantha vepratica, upper face. X5. 



Plate 14. 



Fig. 1. Ophiochondriis grannlaliis, under face. X7. 



2. Ophiochondriis annatiis, upper face. X8. 



3. Ophiodiondrus annalm, uuiIqt iixcc. X8. 



4. Ophiochondrus granulaius, upper face of a small specimen. Xfi. 



5. Ophiochondrus granulaius, upper face of a larger specimen, Ilie under fare of which is illustrated 



in fig. 1. X6. 



6. Ophiochondrus armatus, more enlarged under face of the specimen illustrated in iig. 3. X". 



7. Sigsbeia conifera, upper face. X8. 



Plate 15. 



Fig. 1. Ophiomitrella americana, upper face. X6. 



2. Opiiioinitrella americana, under ia.(^e. XO. 



3. Ophiacantha anomala, upper face of a fairly large specimen. X8. 



4. Ophiacantha anomala, under face of the same. X4. 



5. Ophiacantha anomala, under face of a young specimen. X8. 



6. Ophioleptoplax allantica, upixir iace. X7. 



7. Ophioleptoplax atlantica, under isLce. X7. 



Plate 16. 



Fig. 1. Ophiothrixconenluta, upper iace. X4. 



2. OphiobyrscUa quadrispinosa, upper ia.ce. XL". ■ 



3. Ophiobyrsella qnadrispinosa, under face. X1.7. 



4. Ophiohgimus secundus, upper Vice. XIO. 



5. Ophiologimus secundus, under iace. X12. 



G. Ophiothrix convoluta. upper face of the disk, more enlarged than in fig. 1. X7.5. 



Plate 17. 



Fig. 1. Astrochema ehngatum,, upper t&ee. X3. 



2. Astrochema elongatum, under face of the ■whole animal, slightly reduced. 



3. Astrochema elongatum, under face, more enlarged. X3. 



4. Sigsbeia sexradiata, upper iaee. XH. 



5. >S!'|7S&m scrrarfm/a, under face. Xll. 



6. Sigsbeia conifera, under face. X8. 



