viii. D, 4 Wharton: Some Philippine Thalassemse 263 



b\ Forms possessing more than 3 pairs of nephridia. 



c'. 4 pairs of nephridia. Longitudinal muscle divided into 10 bundles. 



T. decameron Lanchester. 

 c*. Nephridia arranged in paired groups, each group containing a vary- 

 ing number of nephridia. Longitudinal muscle continuous. 



<f . 7 paired groups with 1-3 nephridia in each group T. elegans 



Ikeda. 

 cP. Nephridia in female in 3 pairs. In male in 3 to 8 paired groups 



with 1-4 nephridia in each group T. gogoshimense Ikeda. 



a*. Gephyrea of unusually large size in which the nephridia ai-e indefinite 

 in number, not arranged in pairs, and are provided with terminal 

 funnels. The longitudinal muscle of the dermal muscle layer lies on 



the outside of the circular layer Genus Ikeda Wharton nov. 



b\ Body length 40 cm. Proboscis length 150 cm., nephridia 200-400 in 

 number. Anal trees 6-7 cm. in length, fixed at the tip by a muscle, 

 and covered with tubules bearing funnels.... Ikeda tsenoides (Ikeda). 



Note. T. viridis Verrill, T. verrucosa Studer, and T. papillosum (Delle 

 Chiaje) have not been included in the key. The first two because of the 

 indefiniteness of their descriptions, and the last because I have not seen the 

 description. 



BIBLIOGRAPHY AND GEOGRAPHICAL DISTRIBUTION OF THE SPECIES 

 OF THALASSEMA GAERTNER AND IKEDA WHARTON 



THAIASSEMA Gaertner 



1. Thalassema arcassonensis Cuenot. 



Cuen6t, Proces-verb. Soc. Bordeaux (1902), 6, 1-28. Locality: Ar- 

 chachon. 



2. Thalassema baronii Greef. 



Greef, Nova Acta Acad. German. (1879), 41, pt. 2, 151; Selenka, 

 Challenger Results (1885), 13, pt. 36, 8; Shipley, Proc. Zool. Soc. 

 London (1899), 55; Willey's Zool. Results (1899), pt. 3, 345; Lan- 

 chester, Proc. Zool. Soc. London (1905), 34. Localities: Lazarote, 

 Canary Is. Bahia 7-20 fath., Christmas Is. Lifu, Loyalty Is., 

 Zanzibar. 



3. Thalassema caudex Lampert. 



Lampert, Zeitschr. f. wiss. Zool. (1883), 39, 340; Shipley, Proc. Zool. 

 Soc. London (1894), 472; Willey's Zool. Results (1899), pt. 3, 

 346; Spengel, Verhandl. d. deutsch. zool. Ges. a. d. 120. Jahres- 

 vereins zu Halle (1912). Localities: Red Sea, Indian Ocean, Ro- 

 tuma. 



4. Thalassema decameron Lanchester. 



Lanchester, Proc. Zool. Soc. London (1905), 35. Localities: Chewaka, 

 Zanzibar. 



5. Thalassema diaphanes Sluiter. 



Sluiter, Natuurk. Tijdschr. v. Nederl. Ind. (1888), 48, 244; Shipley, 

 Willey's Zool. Results (1899), pt. 3, 366 and 346; Fauna, etc., Mal- 

 dive & Laccadive Arch. (1902) 1, pt. 2, 128. Localities: Bay of 

 Batavia 110-12 fath., Pigion Island, New Britain, Hulule, Maldive 

 Is., Minikoi, Laccadive Is. 



