14 MOPSEAD.E. 



edge of the branches. Axis articulated, calcareous, solid, expanded 

 at the base ; articulations contracted, short, cork-like or cartilaginous. 

 Branches from the contracted horny articulations. 



* Coral dichotomous ; polype-cells on the edge of the branches. 



36. ISIDELLA. 



Coral branched, furcate. Axis smooth, cylindrical ; stony joints 

 elongate ; branches furcate, proceeding from the corneous joints. Bark 

 rather thick, with irregular opaque spicula. Polypiferous cells pro- 

 duced, subcylindrical. Base of axis expanded, lobed, and branched. 



Isidella, Gray, P. Z. 8. 1857, p. 283. 



Isis (in part), Milne- Edw. fy Haime, Cor all. i. p. 193. 



91. Isidella elongata. B.M. 



Branches very few and frequently anastomosed, round, elongate ; 

 joints elongate, deeply grooved ; internodes narrow. Bark unknown. 



Frutex marinus &c., Seba, Thes. iii. 1. 106. f. 4. 



Isis elongata, Esper, i. t. 65 Latnk. Mem. ed. 2, p. 475 ; Milne- Edw. 



Corall. i. p. 196. 



Isidella elongata, Gray, P. Z. S. 1857, p. 283. 

 Mopsea elongata, Philippi, Wiegm. Arch. 1842, p. 38. 

 Mopsea mediterranea, Risso, Eur. Merid. p. 322, f. 1. 



Hab. Mediterranean; Naples. 



Polypes long, exsert, and not retractile, forming a slender wart ; 

 closed polypes mostly reversed (fide Risso's fig.)- 



The branches of I. elongata are said to be often anastomosed, and 

 for this reason it appears to be separated from /. gracilis ; but I have 

 never seen them in that state (Lamx. Pol. Flex. p. 477). 



92. Isidella gracilis. 



Base expanded, laminated ; stem and branches cylindrical ; 

 branches few; joint of axis rather thick; of upper part elongate, 

 translucent, smooth, white ; articulation swollen. 



Isis gracilis, Lamx. Polyp. Flex. p. 477, 1. 18. f. 1, Enc. Meth. p. 466 ; 



Kollilter, Ic. Hist. p. 140, 1. 15. f. 3; Milne-Edw. in Lamk. Hist. A. 



s. V. ed. 2, ii. p. 476. 

 Mopsea gracilis, Dana, Exp. p. 679 ; Milne-Edw. fy Haime, Corall. i. 



p. 198. 



Hab. West Indies. 



Milne-Edwards places this as a Mopsea, and Isis elongata as an 

 Isis, though it is figured by Esper as with the branches arising from 

 the cartilaginous joints. 



93. Isidella coralloides. 



Branches forked, reddish, very slender ; branchlets remote, rather 

 short. Bark with scattered ascending pajoillce. The calcareous joints 



