Species of British Echinodermata, 121 



ranean and on the southern and western shores of our island, 

 attaining its northern limit at Shetland, where we dredged it in 

 1861 and again in 1863, and descending the eastern coast as far 

 as the Moray Firth. It appears to be wholly absent from the 

 rest of the eastern side of Great Britain. 



Genus XIV. Asterina, Nardo. 



[^Asterina, Nardo, 1834. Asteriscus, Miill. & Trosch. (partly), 1840.]. 



Body convex above, or even gibbous, flat beneath ; rays very 

 short ; whole form somewhat pentagonal. Margin of disk and 

 arms sharp-edged, bordered with short spines, but having no 

 distinct marginal plates. Surface above and below bearing nu- 

 merous fascicles of short spines ; 2-4 spines in each fascicle. 

 Respiratory pores very numerous and conspicuous. Suckers bi- 

 serial. Anus subcentral. Madreporiform tubercle midway be- 

 tween the centre and the margin of the disk. 



Miiller and Troschel formed a genus Asteriscus for the recep- 

 tion of Palmipes placenta and Asterina gihbosaj and thus not 

 only unwarrantably used a genus of their own in preference to 

 adopting and enlarging, if necessary, the generic character of 

 one of those previously described, but united two forms which 

 differ in the character of their whole structure from each other. . 



Asterina gibhosa (Pennant) . 



1777. Asterias gibhosa, Pennant, Brit. Zool. vol. iv. p. 62, no. 49. 

 1805. Asterias verruculenta, Retzius, Dissert, sistens species cog. Asteria- 

 rum, p. 12. 



1841. Asterina gibbosa, Forbes, British Starfishes, p. 119. 



1842. Asteriscus verruculentus, Miiller & Troschel, Syst. der Asteriden, 



p. 41. 



^ Dujardin and Hupe, in their ' Histoire Naturelle des Zoophytes 

 Echinodermes,' published in 1862, say of this species, " Les pedi- 

 cellaires sont nombreuses, setacees, placees entre les plaques "; 

 but, although we have examined it most carefully, we are unable 

 to detect any such organs as are described in these words. But, 

 although true pedicellarise appear to be wholly absent in Asterina 

 gibbosa, there are certain spines in this species which may, per- 

 haps, in some degree discharge the functions of these append- 

 ages. The spines of the surface are usually arranged in groups 

 of three or four together ; but between these groups there will be 

 noticed not unfrequently pairs of spines, of similar character in 

 their general structure to the other spines of the surface, but 

 placed close together at the base, and of slightly arched form, so 

 that the apices can be brought into contact with each other. 

 We seem to have here a transition state between ordinary spines 

 and true pedicellarise : the form and structure is more that of 



