554 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



out the Indo-West Pacific from the coast of Africa to Japan and 

 Polynesia. 



Juvenile Leptoplanidae 



Figure Sb-g 



Many of the specimens in the material were juvenile leptoplanids, 

 hence not identifiable. One specimen (USNM 28671), collected by 

 Reish from algae on Majm-o Atoll, Sta. E-57, Aug. 30, 1956, might 

 possibly be Stylochoplana minuta, as judged by the eye arrangement 

 (fig. 3c) ; this worm is 3 mm. long with 18 eyes on one side, 19 on the 

 other. Most of the specimens collected at Ifaluk Atoll in the Caroline 

 Islands were juvenile leptoplanids, apparently all of one species, that, 

 judged by the eye arrangement, are probably either Notoplana micro- 

 nesiana or Stylochoplana minuta. Apparently at the time of collect- 

 ing, September-October 1953, some common leptoplanid of the atoll 

 had been breeding. These baby leptoplanids were washed from algae 

 in the intertidal zone at Stations 29-B-3, 32-F-5, 39-E-4, 40-F-3, 

 84-E-5, 85-G-2, 142-F-3, and 179-184-N-4. Figure 36 gives the 

 general appearance of these young leptoplanids; this one came from 

 Sta. 39-E-4 and has been returned to the U. S. National Museum 

 as a whole mount (USNM 28677). The others (USNM 28678- 

 USNM 28684) have been returned in the original vials. 



There were five other juvenile leptoplanids (USNM 28672-28676) 

 in the collection made by the Stanford team in the Palau Islands. As 

 judged by the eye pattern, none of these is identical with Notoplana 

 palaoensis Kato (1943), the only mature leptoplanid reported from the 

 Palau Islands. USNM 28672, collected from Sta. 28, July 21, 1955, 

 is 3 mm. long, pale or white, anteriorly expanded, with a few eyes 

 arranged in tentacualr and cerebral clusters (fig. dd). USNAI 28673, 

 from Sta. 47, July 28, 1955, is 2.3 mm. long, dark gray in color, of 

 slender shape, with eyes in two longitudinal bands (fig. 3e) . USNM 

 28674, from Sta. 60, Aug. 5, 1955, is 2.8 mm. long, of slender ruffled 

 form, probably white, with eyes in two bands (fig. 3/). USNM 28675, 

 taken Oct. 12, 1955, at Sta. 220, is 3.5 mm. long, pale, of broad, 

 elongated form with eyes in two somewhat broad bands (fig. 3g) ; 

 traces of incipient copulatory organs are present. The eye arrange- 

 ment somewhat resembles that of the specimen from Sta. 47 (fig. 

 Ze), but the difference in color precludes identity. USNM 28676, 

 from Sta. 258, Nov. 2, 1955, appears definitely identical with the one 

 from Sta. 60 (fig. 3j0 and has not been figm-ed ; it is 4 mm. long, white, 

 thin and ruffled. Tentacles appeared absent in all cases and the 

 usual central elongated ruffled pharynx is present. All have been 

 returned to the U. S. National Aluseum as whole mounts. 



