42 TURBELLARIA OF PLYMOUTH SOUND. 
Family VORTICIDAL. 
Genus 13.—PRovoRTEX. 
23. ProvorTgex BALTICUS (Schultze). 
This species is apparently not common at Plymouth during August 
and September. It occurs between tide-marks, most commonly in 
Wembury Bay. 
24, PROVORTEX AFFINIS (Jensen). 
Among alge on the north- and south-eastern faces of Drake’s 
Island. 
25, PROVORTEX RUBROBACILLUS, Gamble. 
This form is figured and described in my “ British Marine Turbel- 
laria,” pp. 470-1, pl. xxxix, fig. 8, and pl. xl, fig. 12. The constant 
presence of red, rod-like concretions in the intestinal cells and the 
form of the copulatory organ are diagnostic features. 
C. ALLGOCAHLA. 
Family PLAGIOSTOMID AG. 
Genus 14,—PLAGIOSTOMA. 
26. Puaciostoma pioicum (Metschnikoff). 
Duke Rock and Wembury Bay. 
27. PLagiosroma ELONGATUM Gamble (“ British Marine Turbellaria,” 
p. 473). 
A single specimen among sand, Wembury Bay. Mr. Garstang sent 
me two from the Breakwater in November. 
28, PLaGiostoMA PsEUDOMACULATUM Gamble (loc. cit., p. 474). 
Among the weed-tubes of Polydora cxca in the Hamoaze. 
29, Piaciostoma sacirta Uljanin. 
Among weeds in a tide-pool, Redding Point. 
30, PLAGIOSTOMA CAUDATUM Levinsen. 
A single specimen dredged in Cawsand Bay among Zostera. 
