18 ZOOLOGISCHE MEDEDEELINGEN — DEEL IV 



6. Neritina (Neritodryas) subsulcata Sowerby. 



Sowerby. Conch. 111. N. 50, fig. 50. v. Martens. Martini-Chemn. Conch. Cab. 

 Ed. II, Mon. Neritina, p. 142, PI. 12, fig. 11, 12. Tapp. Canefri. Fauna Mal. N. 

 Guinea, p. 72. 



Region of the Mbai-river; Mbai-river, April, 1911. 



Some characteristic specimens have been collected at both stations. 



7. Neritina (Clithon) brevispina' Lamarck. 



Lamarck. An. s. vert. Ed. II, Vol. VIII, p. 572. v. Martens. Martini-Chemn. 

 Conch. Cab., Ed. II, Mon. Neritina, p. 156, PI. 17, fig. 1—4, 9. v. Martens 

 Süss- u. Brackw. Moll. d. Ind. Arch., p. 89. Tapp. Canefii, Fauna Mal. N. 

 Guinea, p. 73. 



Brook flowing in the Kajo-bay, May 28, 1910; rivulet near Oinaké, 

 May 31, 1911. 



Some of the specimens from the first-named locality belong to var. 

 mutica Sow., without spines, those from Oinaké have beautiful colour- 

 markings, consisting of elongated flammules. 



8. Neritina (Clithon) subocellata Schepman. 



Schepman. Notes Leyden Museum, Vol. VII, p. 49, PI. 4, fig. 3. 



Brook flowing in the Kajo-bay, May 28, 1910. 



The specimens are spined, the spines in most cases are well developed, 

 one of them is a remarkable colour-variety, having on a yellowish ground, 

 red spots instead of the usual black ones and two black bands, one reaching 

 from the suture to the spines, the other below the periphery. I wish to 

 call this, var. ex col. bifasciata. 



S e i) t a r i a Férussac. 

 1. Septaria suborbicularis Sowerby. 



Sowerby. Cat. Tankerv. App. p. 10. v. Martens. Martini-Chemn. Conch. Cab. 

 Ed. II, Navicella, p. 31, PI. 6, fig. 5—14. v. Martens. Süss- u. Brack w.-Moll. 

 d. Ind. Arch. p. 84. Tapp. Canefri. Fauna Mai. N. Guinea, p. 84. 



Brook flowing in the Kajo-bay, May 28, 1910; Mbai-river, near the 

 mouth; rivulet in the Tanah-Merah-bay, Aug. 18, 1910. 



Amongst the specimens from the last-named locality, one belongs to 

 the var. furcato-radiata v. Mart. (1. c.) with spiral, furcate, black streaks, 

 instead of the usual net-work. 



