[23] | ENTOZOA OF MARINE FISHES OF NEW ENGLAND. 475 
bothria are reflexed. Neck flattened, rather slender, increasing uni- 
formly backwards and merging imperceptibly into the jointed body, 
covered, sometimes sparsely, sometimes thickly, with very small, 
straight, sharp, bristle-like spines. The body has at first an unbroken 
outline, the square segments being indicated simply by fine, transverse 
lines. Farther back the segments become elongated, with the corners 
slightly rounded. Genital apertures marginal, opening about the mid- 
dle line. 
The compound hooks of the head have three recurved prongs each, 
the middle one slightly longer than the others, the inner one the short- 
est. These prongs rise from a common horizontal part, which is itself 
supported by a flattened or spatulate process, which lies immediately 
under the middle prong, is about the same length and parallel with it. 
The following measurements were made from a mounted specimen: 
Millimeters. 
Lae MOTE Gy" S01 C0 oS i ee ee eee eee Cera are rie ar ep cts 40. 00 
Meme PHVOH NGA ot c= sess a sci Ss's cece snes Atlee Be) fasalee me mrene wisn cee ey aalaateiee 0. 52 
PERCE ROLT HOA =. Lejte<) oteioe = Stine chase ge. cat Be Noes ences aah eae he eee 0. 44 
resapniof neck!) 22062528222. 22. abe SSeS Nel ee ahle caesarean eee 0.12 
Menoth of first) segments, 2™™ from) head. -.25. .32522).2s256 21-2 0520002) 2k-2 0. 03 
PEEMMOD HIS APPMOGNDS ni 2i15 sss kaos dacen cw easnds osc ioe ae Gameaeteas 0.01 
PESO PMONGS, oc LOM NAG . 5 5... cece dessa nn seem sancae wee eae sen 0.20 
[step ueROLeseCTRONLS Oo tTONY NAM ac bores eee eae ce ined Seen ets seme baeceee 0. 42 
Length of segment, 6™™ from head ...--..-...-..----- tL Ne AUR ete poe eps 0. 34 
Breadth of segments, 6™™ from head ....-.---...---- paises 22s aa Pe eee nee 0. 42 
Menoutuorposterioriscomentsl isos 2.2142. nee ld feuds bee is eee cere 2.20 
PEM bheOtmposterior SeoMents: <2 ss.c.caesie fost see oa eces sb oneyeeeeee 0. 84 
Meteo NOOO KS seca. or oe ls. Meee oes el et ee eS ts ls os ays Linn) 
ienecror Drstly spines.on neck or, body +- +. <.4-422 si 46 jo bend sen ceo sees 0. O1 
A few specimens in the lot differed from the prevailing type in being 
much more irregular in outline and ‘having in general a more fragile 
structure. The neck is much distorted by contraction and much 
broader than in the prevailing type; the first segments, on the con- 
trary, are longer and more slender. The posterior segments are ellip- 
tical, oblong, flatter, and more fragile in appearance. 
In one specimen { found what seemed to be a transverse costa on the 
face of a bothrium. I looked in vain for a similar characteristic in the 
other specimens of the lot. If such cost could be proved to be char- 
acteristic of this worm it would indicate a very close relationship with 
Calliobothrium. 
In some the bristly spines were found on the neck and noton the 
body, in others sparsely on the body and not on the neck, in others 
thickly on both neck and body. They are, withovt doubt, the remnant 
of a bristly outer covering of the body, which is characteristic of the 
young and larval conditions of this genus. 
The genus Cylindrophorus is a provisional one made by Diesing to in- 
clude a singlespecies which is not well known. He, however, includes it 
among those Tetrabothric, which are characterized by having no auxil- 
ia”y acetabula on the bothria. The presence of a well-defined auxiliary 
