Is'EW SPECIES OP FLATWORMS — HYMAN 425 



Suborder Terricola 



Family GEOPLANIDAE 



Genus GEOPLANA Stimpson, 1857 



What evidence there is available indicates that Stimpson's Pro- 

 dromus (1857), or at least the signature of the Proceedings of the 

 Philadelphia Academy containing it, was published in February 1857, 

 Avhile the Heft (or fascicle) containing Schultze's quotation of 

 Miiller's diagnosis of the genus was published and first available on 

 May 2, 1857 (Abh. Naturf. Ges. Halle, vol. 4, p. 11 of the Berichte 

 appended to the volume, 1858) . Ascribing the year 1856 to Geoplana 

 MiiUer, as do some authors, seems to be based on the fact that 

 Leuckart referred to the paper in his "Bericht iiber die Leistungen in 

 der Naturgeschichte der niederen Thiere wahrend des Jahres 1856" 

 (Archiv fiir Naturg., Jahrg. 23, Band 2, p. 209, 1857), but this note 

 was published in 1857 and the earliest date assigned to the Miiller 

 descriptio2i of the genus is that of the reprint, "auch als Separat- 

 abdruck Halle 1857" (Leuckart). 



GEOPLANA MEXICANA, new species 



Figure 48, 6, c 



Material examined. — Two specimens, both immature. Larger 

 specimen selected as type. 



Descrijytion. — Type, 16 mm long, 2 mm wide at widest part, with 

 an appearance typical of the genus (fig. 48, 6). Head bluntly 

 pointed, upturned, body increasing in width to about the middle, then 

 tapering to the pointed posterior end. Eyes numerous, extending 

 along the entire margin and across the ventral surface of the anterior 

 end, larger and in single file anteriorly, becoming smaller and less 

 regular in arrangement throughout the middle portion of the body, 

 and few and widely spaced in single file toward the posterior end. 

 About 85 eyes were counted on each side of the type specimen, but the 

 number probably increases with age. 



Color. — A slender middorsal dark stripe, bordered on either side 

 by a wider light stripe, then dark to the lateral margins. The dark 

 part of the dorsal surface is a deep brownish black; the two light 

 stripes are probably yellowish in life. Ventral surface uniform 

 medium brown. 



Rei)roductive system. — The type specimen was cut into serial sec- 

 tions, but unfortunately it was only at the onset of sexuality. Testes 

 numerous, ventral, throughout most of the body length. Copulatory 

 apparatus immature, genital pore not yet formed ; what was present 



