528 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



LEPTOMETRA CELTICA. 

 Fig. 1212, pi. 34. 



P. H. Carpenter recorded that the Porcupine, dredging in 220 fathoms oil 

 Cape Mondego, Portugal, in 1870, yielded a single larva of this species in which 

 the radials have not as yet appeared. He noted that it did not differ in any 

 important respect from the corresponding stage in the larva of Antedon bifida, 

 but the column is a trifle less robust as compared with the size of the head, and 

 the five sacculi, which are so constant in the Antedon larva (one between the bases 

 of every two oral plates) do not appear to be present. 



The figure shows 13 columnals, a circular terminal stem plate, and orals with 

 considerable more eversion of the lateral edges than occurs in Antedon. 



LEPTOMETRA PHALANGIUM. 



Lo Bianco states that the pentacrinoid young of this species are found on 

 the cirri of the adults in June and September at Naples. There is no further 

 reference to them. 



ISOMETRA \aviPARA. 



Both K. A. Andersson and Th. Mortensen have published notices of the penta- 

 crinoids of this species; neither has described them in detail, though the latter 

 will do so shortly. 



Among 11 sexually mature females examined by him, Andersson found 7 with 

 stalked young on the cirri. 



The cirri to which the young are attached are more developed than the others, 

 consisting of usually 34 or 35, seldom of as few as 31, segments, and are directed 

 upward between the arms, while the other cirri, curving downward as usual, are 

 composed of only 27-29 segments. 



The young are always attached near the tips of these longer erect cirri, and 

 always within a sector from 2 mm. to 3 mm. in length. 



One female carried no fewer than 99 young distributed on 8 cirri, which bore 

 30, 24, 17, 12, 9, 4, 2, and 1, respectively. Another had 40 young distributed on 6 

 cirri. All the stages between the oldest and larvae just attached are represented. 



The largest pentacrinoids present are 15 mm. long, the crown being 4 mm. 

 in length. The pinnules are in process of formation, but no cirri have as yet 

 appeared. The terminal stem plate is in the form of a disk which is wrapped 

 about the cirrus. 



Some of the small pentacrinoids are on the stems of the larger ones. 



HELIOMETRA GLACIAU8. 



Figs. 1215, pi. 34, 1226, pi. 37, and 1354, pi. 56. 



Doctor Danielssen records that the Norwegian North Sea Expedition secured 

 a pentacrinoid of this species in latitude 80° 03' N., longitude 8° 28' E., at a depth 

 of 260 fathoms, on August 14, 1878. 



