[35] ENTOZOA OF MARINE FISHES OF NEW ENGLAND. 487 
The head of the living worm is very variable in shape. The bothria 
are lateral and are united at the apex by their margins; usually broader 
than long, slightly emarginate on the posterior edge, with a raised and 
thickened border. The neck is long, cylindrical, the narrowest part 
about half way between the head and the contractile bulbs. There is 
a constriction immediately behind the contractile bulbs, back of which 
the neck swells into a nearly globular base. This rounded basal part 
of the neck is sharply marked off from the body by a short, narrow 
constriction. The body is without segments or transverse markings of 
any kind for a distance equal to as much as six times the length of the 
head and neck. Strive then begin, which outline squarish segments. 
The first segments are a little longer than broad; subsequently they 
become much longer than broad, crowded with ova, and with the geni- 
tal apertures marginal. The four proboscis sheaths are long and 
thrown into spirals, the coils of the spirals being dense or loose, as the 
neck is contracted or not. The proboscides when everted are seen to be 
very long and slender. They are closely beset with small hooks, which, 
when highly magnified, are seen to be of several distinct shapes. The 
prevailing shape of those near the end of the proboscis is slender, taper- 
ing, somewhat irregular in outline, with an abruptly recurved short 
point. Others have the same length, but differ in being broader, and 
in having a curved, convex outline on the posterior edge. Others have 
the same outline, but are very short. Others are slender, curved slightly 
and pointed, but are without the abruptly reeurved point. Some are 
straight, others nearly straight, but bent slightly about the middle. 
The hooks on the proboscides, moreover, are arranged in distinct series 
of ternate groups. This arrangement could be plainly distinguished in 
some places, while in others it was but faintly indicated, and, owing to 
the extreme smallness of the hooks and their peculiar shape, it was im- 
possible, from the specimens at my disposal, to determine the exact 
number of series, or whether, indeed, all the hooks were arranged in 
these ternate groups or not. Where most distinct there seem to be 
four series of ternate hooks. The longer hooks stand nearly at right 
angles to the axis of the proboscis, and are equal in length to about 
one-third of the diameter of the proboscis. 
The following measurements are from an alcoholic specimen : 
Millimeters. 
Length of strobile............ SE Sica elie ie SSUES Die eee ee Boh 31. 00 
Mencia Of DOtnria seca 2 snes eee tobi Aadeaaes bodcsis athena he Si eka 0. 42 
Renu nsOl, DO UND Ate heehee cheese a aL. Mace 5 oli sk catardie nay tarote) wis aisle 0, 34 
Length of head and neck..-... 2.2. ..¢ 2... sence Sop Ra eek ade Ach ated, a iets Ses 2. 00 
Mawern. OL proboscis shearer sess. 2 Sos cewacicetosc ccs ce soe Stereo cee cs eeu 1. 40 
Meneih, Of CONLTACEUE DILDSar seen son se teers Me Te, NEDA ahs Obes 0. 29 
Mhesoirl Oh CQuiractiloypUlussencss <o1t ialee tie OS eee Boe tay oS see 0.10 
Breadth of neck near head (lateral)... .. 2... .o02-0 ceo. ecee ss re eee 0. 24 
emeein OF neck Tear middle (lateral) .. 0 <2occsec cok cas vaje cen saasaseaccieede 0. 20 
Breadth of neck in front of basal Dulbi ssa sasalaeses cael ces eae sesaceedle  Oiom 
