NEW SPECIES OF FLATWORMS — HYMAN 437 



of which Bock figures the copulatory apparatus. Unfortunately, L. 

 iyremellans differs markedly in its sexual anatomy from the great 

 majority of the many species that have been put into Le'pto plana in 

 the hundred years since the genus was founded, and so it becomes 

 necessary to allocate practically all the older Lcftoplana species to 

 other genera. Most of them belong in Notoplana Laidlaw, 1903. Bock 

 does not list any other species but tremellark under Leptoplana. The 

 present species, L. vesiculata^ clearly belongs in Leptoplamz and 

 justifies the concept of a leptoplanid genus built around L. tremeUaris. 

 The distinguishing features of the genus are the wide separation of 

 the genital pores with a genital sucker between them, the well-devel- 

 oped seminal vesicle, the tubular, poorly differentiated granule vesicle 

 without definite external limitation, with a proximal diverticulum, 

 and the small unarmed penis in a long penis pocket. Since L. vesi- 

 culata has a large Lang's vesicle. Bock's definition of Leptopla'aa 

 (1913, p. 181) must be emended to read: "Lang's vesicle developed or 

 rudimentary." 



The only previous publication on the polyclads of the Puget Sound 

 region is that of Freeman (1933). He does not list any species of 

 Leptoplana, and it is obvious that L. vesiculata is not identical with 

 any of the species he describes. Polyclads from the California 

 coast have been studied by Plehn (1896, 1898), Heath and McGregor 

 (1912), Boone (1929), and Freeman (1930). Bock has transferred 

 Plehn's Leptoplana califoimica to the genus Stylochoplana. Heath 

 and McGregor describe four new species of ^''Leptoplana^'' Of these, 

 Z. Tupicola probably belongs to Notoplana, L. timida is probably not 

 a Leptoplana, since it has a large penis and definite granule vesicle, 

 L. saxicola is evidently a Notoplana, and L. inquieta with its com- 

 mon genital pore would also not fit into Leptoplana. Boone (1929) 

 figures '"''Leptoplana^'' scwphila with a chambered granule vesicle 

 (whose nature she failed to understand), and hence this species is 

 either a Stylochoplana or a Notoplana. '■''Leptoplana^'' acticola. is 

 also stated by Boone to have a large granule vesicle (which she calls 

 ejaculatory organ and figures badly), and it must therefore be 

 removed from Leptoplana. After all that has been said by the fore- 

 most students of the Turbellaria on the absolute necessity of a study 

 of serial sections in the taxonomy of this group, there appears to 

 be no excuse for the further publication of taxonomic descriptions 

 based only on whole mount studies. These California forms must 

 be restudied before they can be allocated to the proper genera. 



It thus appears that Leptoplana vesiculata is the only member 

 of the genus so far found on the Pacific coast of the United states. 

 Old descriptions of Leptoplartm species from the Atlantic coast 

 cannot be evaluated until the specimens are reexamined. 



