Occurrence of Gobius capito in Cornwall. 591 
The males of the gobies are to be recognized by the 
urogenital papilla being more attenuate and terminating in a 
point, whereas in the female it is broader and truncate or 
excavo-truncate at the apex. In the former sex of the present 
species also the third, fourth, and fifth rays of the first dorsal 
fin are usually prolonged, the fourth being, in one male from 
Poole, an inch and a quarter in length. ‘They vary, however, 
with individuals, while the rays are only slightly prolonged 
and filiform in the female sex. 
In G. paganellus the rays are not prolonged in either sex. 
The scales are much larger in G. nzger in proportion to its 
size than in either G. paganellus or (7. capito, there being 
never more than forty, counting longitudinally from the base 
of the pectoral fin, along the lateral line, to the caudal fin. 
In a transverse line, counting obliquely forwards from the 
posterior ray of the second dorsal to the posterior ray of the 
anal, there are not more than nine scales, while in a 5-inch 
example a scale removed from the median line at this spot 
measured 3°75 millim. across. In the other two species a 
scale from an example of the same length measures about 
2 millim. across; while there are not less than fifty scales in 
longitudinal series in G. paganellus nor less than sixty in 
G. capito. 
The ventral fin resembles that of G. paganellus in having 
the anterior membrane united along its lateral margins, not 
free and bluntly pointed as in G. capito. 
The first dorsal fin has no pale orange or yellow marginal 
band, as has G. paganellus. 
‘Lhe interorbital space is scarcely more in width than one 
fourth the transverse diameter of the eye. 
So that G. neger may be distinguished from the latter species 
in both sexes by (1) the absence of any marginal orange 
band on the first dorsal fin, (2) by the larger size of the scales, 
and (3), in the male sex and to some extent the female, by 
the prolonged middle rays of the first dorsal fin. 
It may be recognized from G. capito, in all ages of the 
latter, (1) by the anterior membrane of the ventral fin being 
united throughout its margin, (2) by the larger size of its 
scales, (8) by the less proportional width of the interorbital 
space, (4) by the prolongation of the median rays of the 
first dorsal, and (5) by the smaller adult size. 
The following measurements of eight examples from Poole 
Harbour, Dorset, taken in October, will confirm the above 
characterization of the species :— 
