L.M.B.C. TURBELLARIA. 01 



remain firmly attached to its favourite weeds (species of 

 Ceranmcm, &c.). These papillae are elevations of the 

 epidermis. The force of adhesion exercised by them, 

 may be roughly estimated by using a powerful syringe. 

 Repeated action of an in-going or out-going stream do not 

 affect the Convoluta. It merely sways slightly in the 

 direction of the current without in the least loosening its 

 hold on the substratum. This device is general among 

 littoral Turbellaria; some forms indeed {Planaria dioica, 

 Claparede) are provided with adhesive papillae over their 

 entire surface. 



Eggs of Convoluta paradoxa were found in orange 

 clumps (30 — 40 in a clump) during July. Each Qgg meas- 

 ured '07 mm. in diameter, and owed its colour to the con- 

 tained food-yolk. The adult (physiologically a female) 

 becomes a tense bag of eggs which ruptures at the slightest 

 touch. Young Convolutce swim with great ease and 

 rapidity, resembling in colour, form, and movement, the 

 Copepoda associated with them. They contain very few 

 (4 — 8) zooxanthellae and are consequently of a much lighter 

 colour than the adults. 



Convoluta paradoxa has been recorded from Firth of 

 Forth, Berwick Bay, Guernsey, St. Andrews, Skye, Wey- 

 mouth, Millport and Plymouth, and is generally distri- 

 buted in northern and southern European seas. 



5. Convoluta flavihacillum, Jensen (PL XII, fig. 4.) 

 Occurred in tide-pools in front of the Port Erin Station 



during July. It is distinguished from the preceding species 

 by its larger, more robust form, and the absence of zoox- 

 anthellae. 



B. Rhabdoccela :— Family Mesostomid^. 



6. Promesostoma marmoratum, Schlz (PI. XII, figs. 8, 9.) 

 This active littoral species appears to the naked eye as 



a fine whitish thread 1—1.5 mm. long. The body truncate 



