336 MR. R. COLLETT ON CERTAIN GOBIOID FISHES. [Mar. 5, 



The second dorsal has nineteen, sometimes twenty rays, the last 

 of which is a double ray. By means of a strong membrane the rays 

 are directed strongly backwards, and appear, therefore, lower than 

 they really are ; they are all even, and have a length equal to half 

 the height of the body. The posterior rays are not elongated even 

 in the male, and reach to an orbital diameter's distance from the 

 root of the caudal fin. All the rays are indistinctly articulated, and 

 undivided ; and it is only by the aid of the microscope that in some 

 individuals a trace may be seen of an indistinct division at the point. 

 Still shorter and more delicate are the rays of the female, their length 

 being scarcely equal to an orbital diameter. 



The caudal fin has fifteen articulated middle rays, sometimes only 

 fourteen ; also on each side eight, sometimes nine or ten short con- 

 necting rays, which are widely divergent in their points, especially the 

 foremost, so that they can even point forwards, giving the root of 

 the fin an increased breadth. The middle rays are articulated, 

 and all of them divided from about the middle (except the two 

 outermost on each side) ; but neither of the branches is further 

 divided. The first ray is short and thin, and the articulation is not 

 very plain ; the fourth and fifth rays are the longest, while the middle 

 rays again become shorter. One consequence of this is, that the 

 fin becomes more or less emarginate, with rounded edges ; it is 

 rather short, and scarcely attains the greatest height of the body. 



The anal fin counts twenty-one rays, the hinder of which is a 

 double ray. It takes up nearly the whole space between the vent 

 and the caudal, and agrees very much in its form and construction 

 with the second dorsal. It is only by very favourable light that any 

 trace of articulation in the points of the rays can be discovered, and 

 not in all of them. The last ray reaches almost to the root of the 

 caudal ; in some undamaged individuals it is even connected with 

 the last-named fin by a membrane, whilst this membrane is wanting 

 in others. 



The pectoral fin counts thirty, sometimes thirty-one rays. Twelve 

 to fourteen of the middle rays are singly divided from about the 

 middle ; the remainder are undivided. All are finely articulated. 

 The form of the fin is broadly rounded. The pectoral fins are not 

 very long ; in mature males they have about two thirds of the head's 

 length, and do not reach to the vent. In young males and'in the 

 female they are much shorter, although they are never rudimen- 

 tary. 



The ventral fins, which are attached close to the root of the pec- 

 toral fius, and just behind the lower end of the gill-openings, are 

 well developed in the mature male, shorter in the younger male, and 

 rudimentary in the female. 



When present they form a closed and deep funnel, which is square- 

 cut behind, and, contrary to what is found in the other Gobiidce, 

 have their innermost rays (nearest to the belly) shorter than the 

 outer ones. The number of the rays is six in each fin : of these the 

 first is divided from about the middle ; the remainder are more 

 slender, undivided, and not articulated. On the whole, the faint 



