UPlllACTIS VIUKSCENS. 



113 



LIST OF SPECIMENS. 



Catalogue 

 N umber. 



Oripinal I Number 

 Numbur.l of Spec. 



Locality. 



When 

 Collecled. 



Whence obtained. 



Nature of 

 Specimen. 



219 

 220 

 221 

 222 



223 



224 



1020 



1156 

 1109 



MiiscHin of Comparative Zoolorjy. 



St. Tliomas, W. I. 



Capi' Florida. Fi'h. l«.j(i. 



Ki'v West, Fla. Mh. G, 1858. 



Cliarlc'ston, S. C. 



Wost Indies. 



Bahamas. 



Smithson ian Institution . 

 West Indies. 



St. Thomas, W. I. 

 St. Thomas, W. I. 



.\. II. PviisC. 



Tlieo. Lvnian. 

 J. E. Mills. 

 Prof. Ai^assiz. 

 Univei-sity Museum, 



Copeidiajfen. 

 Dr. II. Bryant. 



University IVIuseum, 



Copenhagen. 

 A. II. Riise. 

 A. II. Riise. 



Alcoholic. 



Alcoholic. 



Ophiactis virescens Orsted & Lutkex. 



Ophiacds virescens Lutkex. VIdensk. IMeddelelser. Jan., 1856. 

 Ophiactis virescens Lutken. Addit. ad Hist. Oph., p. 128. 



Special Marks. — In well-grown specimens, the arm is suddenly swol- 

 len near the disk. Arm-spines very thick ; two uppermost usually 

 largest. Upper arm-plates twice as broad as long, with a distinct lobe 

 without, 



Descrii^tion of a Specimen. — Diameter of disk, 3. 8""°- ; from outer 

 side of mouth-shield to outer corner of opposite mouth-slit, 1.6"""- ; width 

 of ann Avithout spmes, 1.1""°'; length of arm, 15'"'"'; distance from outer 

 side of mouth-shields to inner points of teeth, to that between outer 

 corners of mouth-slits, .9 : .9. Mouth-papilla?, four to each angle of 

 mouth ; thin, flat, longer than broad. Teeth six, squarish, flat ; lowest 

 and uppermost one smallest ; those below thicker than upper ones. 

 Mouth-shields much rounded diamond-shape, with a point within, and 

 often a little tail without ; length to breadth, .4 : .3. Side mouth-shields 

 very long and much bent ; they meet within, and run side by side 

 a little way, towards the teeth ; their outer ends meet those of their 

 neighbors, so as to cover the first under arm-plate. Under arm-plates 

 about as long as broad, octagonal, the inner laterals being usually a 

 little longer than the other sides ; length to breadth (eighth plate), 

 .5 : .4. Upper arm-plates oval, much broader than long, with a decided 

 lobe on outer side ; length to breadth (ninth plate), .-3:1; first four or 

 five plates not so broad as those immediately beyond, because the arm 



