Gatty Marine Laboratory^ St. Andrews. 377 



Minute nuchal organs are present on each side just in front 

 of tlie termination of tlie lateral groove, but they are only 

 distinct in life. 'J'he body is about 14: mm. in length, some- 

 what short and thick, tapered at each extremity, rounded 

 dorsally and grooved ventrallj", the powerful ventral longi- 

 tudinal muscles forming a cons[ncuous ridge on each side, 

 almost from end to end. The mouth opens as a small pit 

 behind the isthmus of the longitudinal muscles towards the 

 tij) of the snout. The colour of the dorsum is greenish 

 speckled with dark brownish points, a dark central transverse 

 bar occurring at intervals, so as to give the dorsum a 

 segmented apj)earance. Much of tiiis pigment remains in the 

 spirit-preparation. The ventral surface is pale greenish. 

 The j)OSterior end is abruptly diminished to an upturned 

 caudal process, whicli is terminated by a slightly oblique 

 border (the slope trending from below upward and forward) 

 I'urnished witli sliort and somewhat clavate cirri, two being 

 dorsal and two ventral besides two or three lateral, the most 

 conspicuous pair being the ventral. These form a fringe to 

 the anal aperture, which thus opens into a small funnel. 

 Ihe diminished caudal region is marked by closely arranged 

 circular strias. 



In the groove above each ventral ridge of the longitudinal 

 muscles is a series of dark brown pigment-spots (so-called 

 eyes) at regular intervals, but no bristles are visible except 

 in tlie posterior region, where from live to seven tufts of 

 slender curved glistening bristles form a fringe on each 

 side, sloping downward and backward. Moreover, upon the 

 narrow caudal process a few bristles occur distally on the 

 sides, but their origin is uncertain. The bristles are trans- 

 lucent, taper to a fine point, and do not show evident 

 striations. Small tutts occur considerably in front of those 

 mentioned above, but are only visible under the microscope. 



Like its congeners, it is an inhabitant of muddy sand and 

 swims through the water actively like an eel. 



Wiiilst the caudal region somewhat resembles that of 

 De St. Joseph's Arniandia doUfussi *, it ditfers in the struc- 

 ture of the head, which in the French species has a sleniler 

 })ri)cess {tentaculaire mince, De St. Joseph), in the absence of 

 cirri, and in the inconspicuous nature of the bristles. 



Another species new to Britain is Polyophthalmu,< pictus, 

 which comes from various parts of the west coast of Ireland, 

 Irom Kerry to Galway, and is well known on the French ai?d 



* Ann. 8c. Nat. 8"" sor. t. xviii. \\ 111, pi. vi. tigs. 146-lol. 



