The Blennies: Blenniide 527 
an elaborate series of venom glands connected with the hollow 
spines of the opercle and the dorsal spines. Dr. Gunther gives 
the following account of this structure as shown in Thalasso- 
phryne reticulata, a species from Panama: 
“In this species I first observed and closely examined the 
poison organ with which the fishes of this genus are provided. 
Its structure is as follows: (1) The opercular part: The oper- 
culum is very narrow, vertically styliform and very mobile; it is 
armed behind with a spine, eight lines long in a specimen of 104 
inches, and of the same form as the venom fang of a snake; it 
is, however, somewhat less curved, being only slightly bent 
upward. It has a longish slit at the outer side of its extremity 
which leads into a canal perfectly closed and running along 
the whole length of its interior; a bristle introduced into the 
canal reappears through another opening at the base of the 
spine, entering into a sac situated on the opercle and along the 
basal half of the spine; the sac is of an oblong-ovate shape and 
about double the size of an oat grain. Though the specimen 
had been preserved in spirits for about nine months it still con- 
tained a whitish substance of the consistency of thick cream, 
which on the slightest pressure freely flowed from the opening 
in the extremity of the spine. On the other hand, the sac could 
be easily filled with air or fluid from the foramen of the spine. 
No gland could be discovered in the immediate neighborhood 
of the sac; but on a more careful inspection I found a minute 
tube floating free in the sac, whilst on the left-hand side there 
is only a small opening instead of the tube. The attempts to 
introduce a bristle into this opening for any distance failed, 
as it appears to lead into the interior of the basal portion of the 
operculum, to which the sac firmly adheres at this spot. (2) The 
dorsal part is composed of the two dorsal spines, each of which 
is ten lines long. The whole arrangement is the same as in 
the opercular spines; their slit is at the front side of the point; 
each has a separate sac, which occupies the front of the basal 
portion; the contents were the same as in the opercular sacs, 
but in somewhat greater quantity. A strong branch of the 
lateral line ascends to the immediate neighborhood of their base. 
Thus we have four poison spines, each witha sac at its base; the 
walls of the sacs are thin, composed of a fibrous membrane, 
