[5] ENTOZOA OF MARINE FISHES OF NEW ENGLAND. A5T 
head, is still noticeable on the median segments and also on the poste- 
rior ones, but is not so plainly marked on the latter as on the two former. 
In one specimen examined the first six segments did not show this alter- 
nation in size. In the next fourteen segments, however, the alternation 
was quite evident. The small anterior segments are terete, subtrian- 
gular in outline, narrow in front, wide behind, the length nearly equal 
to the greatest breadth. The succeeding segments are much broader 
than long. At the widest part the ratio of the breadth to the length 
is as much as fourteen to one. As the segments increase in width they 
become much crowded together and thickened. In one specimen, meas- 
uring 140™, the segments increased in width uniformly for about 100™™ 
from the head; from that point they remained about the same size until 
near the posterior end, where they began to be elongated and at the 
same time became narrower and much thinner. The crowding together 
of the median segments is not due to contraction, but seems to be a per- 
manent characteristic of the species. In some very young specimens 
the same character was observed. The general form of these worms, 
both young and adult, was persistent. Although kept for some time 
in water they were not observed to change their form in any essential 
particular from that given in the sketches. 
In alcoholic specimens a dark median line will be noticed extending 
from the posterior end to the middle or anterior third of the strobile. 
This is due to the centrally situated ovaries, which are crowded with 
eggs. The genital apertures are lateral and may be traced in an irreg- 
ular zigzag line on one side from about the anterior third of the body. 
In the mature segments they are rendered obscure, if not wholly oblit- 
erated, by the mass of eggs with which the center of the segment is 
filled. The eggs are white, opaque, oval; length, .045™™; breadth, 
.03™", Associated with these perfect eggs are masses of others which 
become transparent when treated with oil of cloves or other strongly 
refracting media. These seem to be imperfect eggs which have not be- 
come invested with the thick hard shell which covers the perfect eggs. 
An adult specimen gives the following measurements : 
Millimeters. 
MIP SUL OME. Fauciace stan aus ok wee sews ’easteotece ts scat aud ae aaah eee 133. 00 
meraiinet first series Of HOSMONtS. 26/2. 2.0/0.5. Wace ee ae 17. 00 
Ie ORGY ia 2 2k tae tice wot a\minin ois > Pi coiualec ae ae dine) a doe 3. 50 
hres Hoot Head TM tTONt A WIGOSt PATS. 05. <ienc'o apn cicee scence coememecgaceae Pay 00 
Average length of segments in first series........----.--- ---0cecncecedotace= 0.50 
reais Of Widesb SERMONS, Medial: =... l 6 eek cele whee sneeesaace sane 6.50 
Se imo tewiGdesh: SOOMEN TS sIMEMIAM:. = =)2..42sde s2os secs se cens eoacaeoc ese tek 0. 25+ 
Meucth. of posterior, maturesesments..2.2. 2425 sedate: |. oe ASSee 1.00 
Premio Of POSteriOx, MANUF RESMEN TS! 3 2. ale nie od in. ode Dom ne he eee 2.50 
In another specimen the head and first segments give the following 
measurements : 
Millimeters, 
iGgMMmIMLOMBILODILGts- ty setae gd see cle. fom amet tls PSN IO EL ee Orn 
Length of head and first series of segments --..---. 2-2... -- cneeee connen ences 30. 00 
SIRI MOQ: oo tae tee ee cal a do a'e, ewe ee wad oae'cs a Tae sae esas a perceims 3. 00 
