684 PATAGONIAN EXPEDITIONS: ZOSLOGY. 



and looped in XII or even extends into XI. The atrium and ductus 

 ejaculatorius exhibit no features requiring special comment, which is 

 true of the ovaries also (Plate L, fig. 15). The collection includes one 

 specimen of 8 mm., bearing eggs arranged in a compact group at the 

 widest part of the body. Others exhibit indications of having recently 

 borne eggs or young. 



Alimentary Canal. The pharynx is about as stout as that of G. lineata, 

 and when retracted reaches from VIII to XII. Its free end is provided 

 with muscular denticulations. In XIII the thick ducts of the pharyngeal 

 glands open into its posterior end. These ducts are provided with a 

 stout muscular sheath, are single on each side and lack any cross connec- 

 tion. The glands consist of a few cells which are individually of larger 

 size than in G. ditplicata and are distributed sparingly over somites XI to 

 XV or even beyond. There are usually only five pairs of gastric caeca, 

 the first four of which are simple and of nearly equal size, the fifth, which 

 arises in XIX, is somewhat spacious and reaches XXII. The intestinal 

 caeca are four pairs, alternately larger and smaller, and, with the excep- 

 tion of the last, curve somewhat cephalad above the last pair of gastric 

 caeca (Plate XLIX, fig. u). 



G. simplex is represented from the following localities : 



No. 5. "Spring on Rio Chico 15 miles above Sierra Oveja." 6 

 specimens. 



No. 14. "Rio Chico, 5 miles above Sierra Ventana, Feb., 1899." 

 15 specimens, several bearing eggs and young. 



No. 22. " Large spring 30 miles above Sierra Oveja, Rio Chico, Feb., 

 1899." 2 specimens. 



No. 38. "Spring on Rio Chico 25 miles above Sierra Ventana, Mar., 

 1898." i specimen. 



No. 40. "Spring 25 miles north of Sierra Oveja, Mar., 1898." 2 

 specimens. 



No. 48. Rio Blanco. 2 specimens. 



No. 36. "Spring on Rio Chico 30 miles above Sierra Oveja, Mar., 

 1898." i specimen. 



" In spring on Rio Chico." i specimen. 



