1907.] NATURAL SCIENCES OF PHILADELPHIA. 145 



A NEW TURBELLARIAN FROM HAWAII. 

 ; ■ " BY HAROLD HEATH. 



The species of flatwonn described in the present paper is represented 

 by four individuals dredged by the U. S. F. C. Str. "Albatross" in the 

 Auau Channel between Maui and Lanai Islands, Hawaii, where the 

 depth is 28-43 fathoms and the bottom consists of sand and gravel. 

 With one exception the specimens were in perfect condition and swam 

 actively by means of undulatory movements of the lateral margins of 

 the body, as is the habit of several other species of Turbellaria. Cocaine 

 was used as a narcotizing agent and formaldehyde as a preservative. 



The largest specimen is almost circular in outline and measures 35 

 by 39 mm. ; while the next largest is more oval with a length of 42 mm. 

 and an average width of 27 mm. In each case the body is only slightly 

 colored and is restricted to the dorsal surface, where the minute black 

 pigment cells form stippled streaks and blotches. As in other Plano- 

 ceridae the mouth is about median, the male copulatory apparatus is 

 directed backward, and in common with other species of the genus 

 Flanocera the nuchal tentacles are located about one-foiu-th of the 

 body length from the anterior end. Around the bases of each there 

 is a group of large eyes, while the intermediate brain region is occupied 

 by the smaller voriety which forms two irregular clusters. 



The digestive system presents no especially peculiar features. The- 

 external mouth, mesially situated, leads into the much plicated, 

 pharynx (PI. XIV, fig. 1), whose length nearly equals one-fourth that of 

 the body. Laterally it is produced into four pairs of diverticula, of 

 which the anterior may be somewhat indistinct. Directly above, 

 that is dorsal to the outer mouth, the opening from the pharynx leads 

 into the main division of the gut, which in turn communicates with five 

 pairs of intestinal branches. These are invariably empty and rela- 

 tively slender and practically of even calibre throughout their entire 

 extent. Their general arrangement and method of branching may be 

 seen in fig. 1, which likewise shows frequent anastomoses, Lang* 

 states that when these occur they appear most clearly in the young 



^ Die Polydaden, Fauna und Flora des Golfes von Neapel, 1884. 

 10 



