1886.] MICROSCOPICAL JOURNAL. 165 



f. Semi-cells triaugulai- ; sinus with a small spine on each side, Leivisii, 122. 

 f. " " sinvis without a spine . . art'stiferum^ 122. 



f. Semi-cell quadrangular, margins toothed or spinous, quadrangtilare^ 145. 



g. Angles in end view trifid trijidtun^ 123. 



g. '• '' '' simple or bifid (^ss) 



h. Arms trifid or bifid ; end view 3-4 radiate ; arms smooth, brachiatum^ 1 24. 



h. " " "■ end view 3-radiate ; arms aculeate, rough, 



aspiitosum^ i43- 



h. " " " end view 5-6 radiate .... distentttm^ 149. 



//. . "• " " end view 7-9 radiate Rotiila, 13^. 



//. Arms truncate, oblique, geniculate, short; end view 4-radiate, 



inconspicuum^ 125. 

 h. Arms acute or aculeate, curved ; end view 3-radiate . . sudeticum.* 



i. Ends separated by a more or less elongated isthmus {J) . 



/. Ends approximate {z) . 



j. End view fusiform, with a central obtuse inflation . leptocladum^ 136. 

 j. '' oval, a long arm on each side, 



grallat or 1711)1^ 136 ; iingitlatnm^ 136. 

 j. End view triangular or 3-radiate {^k) . 

 j. " quadrangular or 4-radiate (^). 



j. '^ 5-radiate {v) . 



j. "■ 6-radiate (w). 



j. " 7~8 radiate Ophiura, 134. 



k. Isthmus basally inflated, cuspidate or spinous (/) . 



k. *•' not basally inflated, cuspidate not spinous (w). 



/. Isthmus basally inflated eloiigatum^ 130. 



/. " v^dth a 1-4 cuspidate protuberance on each side; arms short, 



fasciculoides^ 130- 



/. " with I notched spine on each side .... sphiostiju^ 139. 

 7n. Diameter -^\^ in. (50//) or less {n) . 

 ni. " ^1^ in. (60//) or wider (o). 



n. End straightish, sides tapering into short, mostly obtuse processes, 



tricorne^ 126. 



n. End broadly convex ; processes curved cyrtocerum^ 128. 



n. " '' processes straight, slender . . . gracile^ 133, 



o. In end view the angles produced in long arms, 



vestitiim^ 138 ; pseiidosebaldi^ 139. 

 o. In end view the angles not produced in long arms . . Sebaldi^ 138. 

 p. Isthmus basally inflated or cuspidate (r). 

 p. Isthmus not basally inflated nor cuspidate (5). 



r. Isthmus basally inflated, corrugated and denticulate . tetragomi7n^ 130. 



)'. " with a short spine on each side odo7itatti77i, 134. 



s. Diameter ^^ in. (31/^-) or smaller (/) . 



s. " lio i"- (6o,a) or larger {u) . 



t. End straight, sides tapering into short, mostly obtuse processes, 



t/-icorne^ 126. 



t. End convex ; pi^ocesses short, stout C7'e7i7ilatu?77, 126. 



t. End concave ; processes short, upwardly diverging, 



piisilhi77i^ 130 ; Do7i7ienii^ 132. 

 u. Processes short, robust, incurved ; end of semi-cell truncate, ce/'astes^ 133. 

 ti. " long, narrow, incurved ; end of semi-cell convex, 



a7ikvi'oidcs^ 137- 



* Journ. R. Micr. Soc, Dec, '85. 



