LIMAPONTIA. 29 



but very contractile ; the sides slightly overhanging the foot : 

 head truncated in front and flat at the sides, except where it is 

 elevated into two crest-like ridges, arched from behind forwards ; 

 on the sides of which posteriorly the eyes are placed in a pale 

 circular space, which is prolonged into the crest : vent sub- 

 posterior. The general colour is black, but sometimes indi- 

 viduals are found transparent and nearly colourless, showing 

 the greenish biliary organ through the skin. L. 0*14. 



Habitat : On Confervas [and small seaweeds] in rock-pools 

 [and among Zostera marina] between tide-marks ; Berwick 

 Bay (Johnston) ; Cullercoats (A. Hancock) ; Whitburn, Dur- 

 ham (Howse); Torbay (Alder) ; Falmouth (Cocks). [Shetland 

 (J. G. J.); Scandinavian coasts (Miilier and others) ; Heligo- 

 land (Frey and Leuckart) ; Brittany (Tasle).] 



This curious little animal is probably pretty generally dif- 

 fused, but on account of its minute size it may readily be 

 overlooked. It is gregarious ; and, wherever met with, it has 

 usually been found in abundance, appearing when contracted 

 like little black dots scattered over the Conferva on which it 

 feeds. When bruised it has a peculiar sweetish smell, which 

 seems to be derived from the seaweed. [It swims in a reversed 

 position, and when disturbed rolls itself into a ball ; sometimes, 

 while floating, it turns itself round in a short coil. This tiny 

 sea-slug has a quaint and " auld warld " aspect.] 



[Fasciola capitata, Mull. Yerm. Helm. p. 79 : this specific 

 name ought to be used. Also PI anuria limacina, Fabricius.] 



2. L. depressa, Alder and Hancock. 



L. depresm, A. & H. in Ann. N. H. 3rd ser. x. p. 264 ; Hancock in Tynes. 

 Club Trans, v. p. 315, pi. 17. 



Body oblong-ovate, depressed, swelling behind the centre 

 and terminating in a blunt point posteriorly ; black, generally 

 with minute yellowish-white spots or freckles : head rounded 

 in front and slightly angulated at the sides ; the lateral crests 

 less elevated than in L. nigra, with the eyes situated in a 

 white oblong area at the side of each : vent placed in a depres- 

 sion at the posterior extremity of the body. L. 0-4. 



Habitat : On a Conferva ( Vaucheria submarina'?)m brackish 



