106 



BULLETIN 76, UNITED STATES NATIONAL MUSEUM 



plates, sometimes spiniferous proximally; straight pedicellariae ovate to lanceolate, 

 acute, not spatulate or dentate; crossed pedicellariae with one enlarged tooth on the 

 outside of the expanded lip of each jaw (pi. 52, figs. 3 and 5); the tooth is not greatly- 

 larger than the other terminal teeth. Young of three species known to have a six- 

 rayed fissiparous stage, unlike adult in appearance. 



Name. — I separated this genus from Coscinasterias and Distolasterias in my 

 Preliminary Synopsis of the Asteriidae (1923). I had not then seen a specimen of 

 Sclerasterias guernei Perrier, for which I gave certain differential characters, following 

 the circumstantial account by Perrier 37 and the notes of Koehler. 38 Sclerasterias 

 had been considered, in America at least, as a very unusual small asteriid, related 

 to the Coscinasterias group. Undue emphasis was placed upon the thick integument. 



During a visit 



- • / 



a visit m 

 November, 1923, to the 

 Musee Oc6anographique 

 of Monaco I had an op- 

 portunity to examine the 

 type of Sclerasterias guer- 

 nei; and through the kind- 

 ness of Dr. Jules Richard, 

 director of the museum, I 

 was permitted to retain 

 for further study a very 

 well preserved ray, from 

 which were taken the 

 pedicellariae figured on 

 Plate 52, Figure 1, la. 

 (Fig. 16 on the same plate 

 is from a specimen pre- 

 served in the British 

 Museum.) 



For some curious 

 reason Perrier figured the 

 most immature specimen 

 of the four, and apparently his description is based upon this undeveloped example (or, 

 since he ignores the other specimens, more probably upon the picture). It is equally 

 strange that the resemblance of the larger specimens to his Stolasterias neglecta was 

 not noted. For instance, Perrier says that there are no intermarginal papulae and 

 only a single series of dorsolateral papulae. The original type, station 57, has two rows 

 of dorsolateral papulae at the base of the ray, and I was able to follow this double 

 series fully three-fourths the length of one ray. There is a well-developed series of 

 intermarginal papulae, but as yet no actin'al papulae, although a few actinal plates 

 have made their appearance in a specimen from station 60 (listed by Perrier). 



The skeleton is precisely similar to that of very small specimens of the genus 

 which I had called Eustolasterias. The superomarginals and lateral face of the infero- 



Fios. 1-3.— 1, Sclerasterias euplecta. The smallest symmetrical six-hated 

 specimen r 5.5 mm. the dotted lines indicate plane op cleavage. the four 

 madreporites are indicated by dots; x3. 2, sclerasterias heteropaes. indi- 

 viddal regeneratino three new rays and two new madreporites; x3. 3. 

 Same; a more advanced stage. In one specimen similar to this the madre. 

 porite o is lacking; x3. 



"1896, p. 35, pi. 1, fig. l.lo. 



"Faune de France, 1921, p. 26, fig. 20. 



