166 Proceedings of the Boyal Physical Society. 



Day says |rds; (2.) the short fusiform and ropidly tapering 

 body ; (3.) the unusual delicacy of the membrane connecting 

 the rays of the vertical fins, which may never be described as 

 robust or fleshy, and is certainly more delicate than that of 

 any other British species ; (4) the usual, if not invariable, 

 presence of the paired latero- ventral ocelli ; (5.) the rounded 

 posterior margin of the operculum. I should, however, state 

 that in two of the specimens from Guernsey, which Professor 

 M'Intosh has kindly lent me, the head is not so wide as 

 usual, but the fins, both in the number of their rays and 

 in their general delicacy, agree with typical specimens. 



This species is generally distributed around the British 

 Islands, but, so far as my experience goes, it is not frequent 

 in Scottish w^aters, and it is possible that a number of the 

 specimens already on record may belong to the form next 

 described. I have obtained it off Ardnamurchan and also in 

 the Gairloch in 8 to 12 fathoms. It has also been dredoed 

 off Colonsay by my friend Mr W. L. Calderwood. 



4. L. MICROCEPHALUS, n. sp. 



? L. Couchii, Saville Kent. 



The following is the formula of the vertical fins : — D., 5 ; 

 A., 6 ; C, 17-19. 



This form bears a general resemblance to Z. himacidatus, 

 but may be distinguished by the following characters : — 

 (1.) the skin is thick and loose as in L. Decandolli ; (2.) the 

 membrane of the vertical fins is more ridd, and there is 

 a special fleshy thickening at the anterior extremity of the 

 dorsal, and also, though usually less marked, at the anterior 

 margin of the anal ; (3.) the anal fin consists of one ray 

 more than the dorsal, whilst the reverse is the case in L. 

 himacidatiis ; (4.) the caudal usually contains 10 to 11 

 prominent rays, instead of 12 to 13 as in L. himaculatus ; 

 (5.) the head is relatively narrow, its width being equal 

 to about two-thirds of the length ; (6.) the trunk is relatively 

 more elongate, and tapers gradually to the tail (<?/. PI. VII., 

 Figs. 4 and G) ; (7.) the median disc of the ventral acetabulum 

 is narrower, and its lateral margins are nearly straight ; 



