L.M.B.C. NEMERTIDA. 219 



Tetrastemma immutahile, Kiclies. 



Average length 5 mm. Fomid among the masses of 

 zoophytes at " The Clets." The body is romided and of 

 a pale yellow with a dark brow^n dorsal band running the 

 whole length of the body. 



Tetrastemma candidum, 0. F. Miiller. 



Average length 1 cm. Fairly common in Port Erin 

 Bay. The colour-varieties met with are the pale yellow 

 and the yellowish green. Some examples had well 

 developed gonads in April. 



Tetrastemma melanoceplialmn, Johnston. 



Mr. Beaumont obtained a specimen from Poyllvaaish 

 in April, and Mr. Vanstone has since collected several of 

 a green variety in the coralline pools near Spaldrick Bay, 

 Port Erin. This variety was 5 cm. in length, and lived 

 for several weeks in captivity. 



Tetrastemma vermiculatum, De Quatrefages. 



Average length, 2 cm. Found at '' The Clets " among 

 tufts of Grisia ehurnea. The colour was pale orange wdth 

 a white dorsal line. The anterior and posterior eyes on 

 either side were united by a band of dark pigment. 



Tetrastemma robertiance, MTntosh. 



Length, 2 cm. One specimen was found during July, 

 1893, in company with Amphiporus lactifloreus. The 

 yellowish body bears on its upper surface a median white 

 line and two lateral brown stripes, which take their origin 

 in a transverse pigment band behind the posterior pair 

 of eyes. 



Family Nemertid^, Hubrecht. 



Nemertes neesii, Oersted. 



Average length 7 — 8 cm. This species is very common 

 under stones and amongst gravel, from high to low-water 

 mark on the south side of the Bay, and also at low- water 

 off Traie Veg. The colour is usually brown on the dorsal 



