REPORT ON THE OPHIUROIDEA. 263 



number of forkings, 1 and in the comparative equality in length of the intermediate 

 shafts. While a large Gorgonocephalus agassizii would have not more than a dozen or 

 fourteen forkings from the main stem, this species has more than thirty ; and the twigs 

 from each of these forkings are generally very rich in forks. In this respect, however, 

 the left stem is very poor as compared with the right. For example, the twelfth twig of 

 the left stem has but eight forks, while the twelfth of the right stem has nearly three 

 hundred. Some of the twigs on the outer part of the right stem have more forks than 

 those further in ; thus No. 12 has more than No. 5. 



Simon's Bay, Cape of Good Hope ; 10 to 20 fathoms. 



Species of Gorgonocephalus not herein described. 



Gorgonocephalus arborescens, Agas., Mem. Soc. Scien. Nat. Neuchatel, vol. ii., pis. iv., 

 v., 1839. 



Stella arborescens, Rondelet, De Pise, p. 121, 1554. 



Euryale costosum, Link., Hist. Anim. sans Vert., vol. ii. p. 538, 1816. 



Astrophyton costosum, Agas., Mem. Soc. Scien. Nat. Neuchatel, vol. ii. p. 11, 1839 (Gorrjono- 



cepJialus in the plates). 

 Astrophyton arborescens, Mull. & Tr., Syst. Ast., p. 124, 1842; Lym., 111. Cat. Mus. Conip. 



Zool., No. i. p. 181 ; Bull. Mus. Comp. Zool., vol. i., part 10, p. 313, note ; Ludwig, Echin. 



des Mittelmeeres, p. 552. 



Mediterranean ; West Indies. 



Gorgonocephalus lamarckU, Lym. 



Asterias caput medusae (1), Linn., Fauna Suecica, 1761, No. 2115. 

 Astrophyton LamarcJdi, Mull & Tr., Syst. Ast., p. 123, 1842. 



North European Seas. 



Gorgonocephalus eucnemis, Lym. 



Asterias caput medusa', Fabr., Fauna Groenl., No. 367, 1780. 

 (?) Zottenkopf, Knorr Delicia Nat. Select., voL ii. p. 34, pi G, figs. 1, 2. 1787. 

 Asterias caput medusae, Dewhurst, Nat. Hist. Ord. Cetacea. 



Astrophyton eucnemis, Mull. & Tr., Syst. Ast., p. 123, 1842; Ltk., Addit. ad Hist., part 1, 

 p. 70, pi. ii. figs. 17-19; Lym., 111. Cat. Mus. Comp. Zool., No. i. p. 181. 



Greenland; N. E. North America. 



1 See T. Lyman, Mode of Forking among Astrophyton.s, Proc. Bost. Soc. Xat. Hist., vol. xi.v. p. 7, March lsTT. 



