REPORT ON THE OPHIUROIDEA. 261 



Table of Species of Gorgonocephalus. 



One madreporic shield inside the raised mouth ring, and at base of a month | , , 



angle. Disk covered by a fine, close, smooth granulation, . . ) Gorgonocephalus arborescent. 



Disk set above and below with short toothdike spines, which are longer ) ,., , , , 



and closer on radial shields, f Gorgonocephalus lamarckzi. 



Disk with small, smooth, scattered grains, which are more numerous on ) r , , , 



the radial shields, . . } Gorgonocephalus eucnerms. 



Stands between the preceding and Gorgonocephalus aqassizii (var. of ) ,, , , 



Gorgonocephalus eucnemis (1), .' . ! . . J Gorgonocephalus malmgm,,,. 



Similar to Gorgonocephalus eucnemis, but with closer, more regular granular 1 r , , , 



tion, and a strong row of grams along genital openings, . . / Gorgonocephalus caryi. 



Disk set with a few small, irregular stumps, which are most numerous on I ,-, , , 



outer ends of radial shields, . . . . . ) Gorgonocephalus agassmt. 



Disk above closely beset with short) thick, thorny stumps; and below I ., . , , . , .. 



with very small short spines, . . . . .) Gorgonocephalm hnckn. 



Disk similar to Gorgonocephalus linclcii, but smooth below, . . Gorgonocephalus stimpsoni. 



Disk set above with scattered minute conical stumps, or stump-like ) „ , , , , .. 



granules. Arms in the adult nearly smooth, . . \ Gorgonocephalus pourtalesii. 





T3 i 



& 

 T3 



p 



O 

 O 



Similar to Gorgonocephalus pourtalesii, but structure more delicate. The } 



young has a simple under arm plate, which is in several pieces in '. Gorgonocephalus chilensis. 

 Gorgonocephalus pourtalesii, . . . . . . I 



Disk finely and smoothly granulated, and set, together with upper surface ) .-, , , 



c J .., , 1.1 i. u i > Gorgonocephalus verrucosus, 



ot arms, with laroe smooth tuhfirn es. . . f " r 



of arms, with large smooth tubercles, 



Radial shields set with fluted stumps. Tentacle scales fiat, and strongly \ r , , , ... 



toothed at the end, . . . . . . . / Gorgonocephalus austrahs. 



Large conical spikes on upper disk, and upper surface of arms, . . Gorgonocephalus mucronatus. 



live madreporic shields, one at inner angle of each mterbrachial space. Surface .-, , , 



. ,. , r , ' ., ° r > Gorgonocephalus cacaohcus, 



of disk and arms smooth, . . . . . . J " * 



Gorgonocephalus pourtalesii, Lym. (PI. XLV. figs. 2-5). 



Astrophyton Pourtalesii, Lym., 111. Cat. Mus. Comp. Zool., No. viii. part 2, p. 28, pi. iv. figs. 



41-43, 1875. 

 Astrophyton Lymani, Bell, Proc. Zool. Soc, p. 99, January 1880. 



This widely spread animal is found from Heard Island to East Patagonia over a region 

 between long. 70° E. and long. 70° W., 220 degrees in all, or more than half round the 

 southern end of the world. The western specimens from Heard and Kerguelen Islands 

 usually have the disk spines sharper and more numerous ; and the basal shafts between 



(ZOOL. CHALL. EXP. — PART XIV. 1882.) 34 



