ECHINODERMATA. 525 



only different ages of Ophiolepis ciliata, and have recognised 

 in Ophiomyxa lubrica, Forb., their Ophiomyxa pentagona ; 

 in Amph'mra negkcta and Chiajii, Forb., their Ophiolepis squa- 

 mata and filiformis ; as well as in Goniaster abbensis, Forb. 

 their Astrogonium phrygianum. Miiller and Troschel are also 

 induced to unite the genera Ophiothrix and Ophionyx, since 

 not only the latter is furnished with many-toothed booklets 

 beneath the rows of spines of the rays, but these organs also 

 occur in Ophiothrix, though with this difference, that the 

 latter Ophiuridaii presents these booklets only at the ex- 

 tremity of the rays, whilst in the former they are placed 

 along their whole length. 



The development of the Asteridse has been described by 

 Sars (Archiv, 1844, Bd. i, p. 169 ; or Annales d. Sc. Nat. 

 t. ii, 1844, p. 190), whose observations were made on the 

 ova of two new Starfishes, viz. Echinaster sanguinolentus and 

 Asteracanthion Mullen. The ova lie upon the surface of the 

 abdomen, which is hollowed out so as to constitute a mar- 

 supial pouch. The Echinaster sanguinolentus of Sars is more- 

 over, according to Miiller (ib. 1844, Bd. i, p. 169), the Echi- 

 naster Sarsii described by himself and Troschel. 



Miiller (ib. 1843, Bd. i, p. 131) has described two new 

 Comatulse as Alecto purpurea and Wahlbergii, and has sup- 

 posed that the Echinodermata described by Retzius as 

 Asterias multiradiata andpectinata, and preserved at Lund, 

 probably belong to the Crinoidal genus Actinometra in- 

 stituted by him. The Comatula?, but very briefly noticed 

 by Lamarck, have been more particularly described by 

 Troschel (ib. p. 135) from the original specimens, as, Alecto 

 carmata, Adeonce, Solaris, brachiolata, rotalaria, andfimbriata. 

 Miiller has given a very important memoir on the structure 

 of Pentacrinus caput Medusa. (Abhandlungen der Akademie 

 der Wissenschaften zu Berlin, a. d. I. 1841 ; Berlin, 1843, 

 p. 177.) He had obtained a specimen from the West Indies, 

 which, after a preliminary historical review of the researches 

 hitherto instituted respecting the Crinoidere and Pentacrinus, 

 is described with the greatest particularity. The stem in 



