iEQUOREAL PIPEFISH. 
681 
The iEquoreal Pipefish is the largest of all our 
Syngncitliince. It attains a length of at least 6 dm." 
The females are largest, their usual size in Scandinavia, 
according to Fries, being 45 — 55 cm., while the length 
of the males is usually between 32 and 40 cm. The 
form of the trunk also shows a considerable sexual dif- 
ference. It generally displays more lateral compression 
than in the preceding forms, but most in the females, 
this being due to the more or less advanced develop- 
ment of the dermal carina that runs along the dorsal 
and ventral margins of the trunk, but which is want- 
ing in the males and young specimens. The tail is 
more slender and more terete (its section more circular) 
than in. the preceding forms. A section of the trunk 
shows an oval, octagonal form, in the females pointed 
at both ends; the section of the tail is a rounded square. 
The greatest breadth of the trunk measures in the fe- 
males about 70 %, in the males about 90 % of its 
greatest depth; the young specimens stand about mid- 
way between these two extremes. The greatest depth 
of the body in the males is about 2 7 2 %, in the females 
about 2 3 / 4 % of the length thereof. At the beginning 
of the tail the depth of the body measures in the fe- 
males about 60 %, in the males about 70 % of the 
greatest depth, or in the former about 11%, in the 
latter about 12 or 13 % of the length of the base of 
the dorsal fin. 
In addition to the above-mentioned generic cha- 
racter that the caudal rows of plates form a continuation 
of the two uppermost rows of the trunk on each side 
of the body, this species and the following one are 
especially remarkable for the great number of rings on 
the body, a number which, at least in this species, may 
rise to 100. The last caudal rings are so small, how- 
ever, that they can scarcely be counted with the naked 
eye. The so-called occipital plates are without Carinas, 
but are as usual grooved; the anterior is about half 
the size of the posterior. 
The head is most like that of the Lesser Pipefish, but 
is comparatively smaller, with smaller eyes and with less 
prominent carina? both on the snout and especially on 
the gill-cover, where scarcely a trace of a middle carina 
can be found. The snout is terete and straight, ascend- 
ing only slightly. The forehead is hollowed into a long, 
shallow concavity. The length of the head varies in 
adult specimens between about 7 l / 2 and 9 % (7.6 — 8.8 
%, according to our measurements) of that of the body. 
In young specimens (between 12 and 17 cm. long) the 
length of the head measures about 27 % of the distance 
between the dorsal fin and the tip of the snout, in old 
specimens 22 — 247 2 % thereof. The length of the snout 
varies between about 44 and 54 % of that of the head, 
and generally begins to exceed V 2 of the latter in spe- 
cimens 37 cm. long. The postorbital length of the head 
varies between about 43 and 38 % of its entire length, 
and this percentage generally begins to sink below 40 
in specimens 37 cm. long. The longitudinal diameter 
of the eyes may measure about 14 % of the length of the 
head even in specimens 35 cm. long; in specimens 44 cm. 
long it measures about 7m °f the same. The least depth 
of the snout varies in different individuals and according 
to age between about 29 and 18 % of its own length. 
The dorsal fin is of fairly uniform height, this 
being always distinctly greater than the depth of the 
body at the vent. It begins at a distance from the 
tip of the snout that in the males does not exceed 
35 % (3l7 2 — 347 2 %•> according to our measurements) 
of the length of the body, but in the females (at least 
the older ones) does not fall below 37 % thereof 6 . The 
length of its base increases with age from about 12 % 
to 1 4 1 / 3 % of that of the body. The vent lies below 
the posterior part of the fin, at a distance from the 
tip of the snout that in the males measures about 39 7 2 
— 437 2 % (39'6 — 43‘6 %, according to our measurements 
of specimens between 12 and 37 cm. long), in the older 
females 47 — 49 % of the length of the body. One re- 
sult of this is that the length of the trunk behind the 
gill-covers, in young specimens less than 17 cm. long 
(we have never examined any young females), measures 
only slightly more than 1 j 2 (about 51 %), in the older 
males about 3 / 5 (59 — 64 %), and in the older females 
about 7 4 (74 — 78 %) of the length of the tail. In these 
differences, depending on age and sex, lies the most im- 
portant character that has been employed as a specific 
distinction between Nerophis cequoreus (?) and Ner. 
anguineus (cf). 
a From Ireland we hear of still larger specimens. “Last winter,’’ writes Blake-Knox in August, 1866 (Zoologist, vol. XXIV, p. 508)^ 
“I met with an immense fish of this kind: seeing a boy “whacking” a donkey with a gutta-percha stick, as I thought, I asked him where 
he got it. “It is only a stalk of a snot (seaweed), sir; see:” and I did see a fine asquoreal, 3 feet 5 inches long. Of its toughness you 
may judge. Is not uncommonly taken in the baskets with whelks and crabs.” 
b Kroyer, however, mentions a female (sign. B among the specimens mentioned by him) in which this sexual character is absent. 
