458 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [6] 
Millimeters. 
Breadth.of headin front, widest part. -.. 20.02... <0 sces Uaensecestdseeesneeee 0.90 
Breadth of head just behind the front rim..........---.--------- oon erp Ree 0. 80 
Breadth of marginal lobe, about the middle... ......... 226 sennen-osecncscese 0. 90 
Breadth of head, narrowest Part... ..- 5-2... 2222-2. woes cto cae on =e ce eee eee 0. 21 
Breadth of first segment, widest (posterior) part........-.....-.--.---------- 0. 80 
Breadth of first segment, narrowest (anterior) part ........-.--2-e-.--- «+. eee 0. 42 
Length of longer alternate segments, first series .... .-.--.---. ..---- -----+--- 0. 40 
Length of shorter alternate segments, first series.....:..-.----..---.-- 
seep anes 
The segments of the first series are sometimes notched or crenulated 
on the postero-lateral margin, with a single median indentation; in 
others the edge is but slightly waving; in others it is nearly entire. 
The following measurements are from a young specimen: 
Millimeters. 
Banothiorehrobile ss 202 i225 0as SPSS SRS ha ce a okie h Seee eaee aoe eee 20. 00 
HMenathiot bead! eves. ce a See ee oe Datei Ts Ee sys2e Ae 2.10 
iBresdubvot head; anterion?. 2/2 2s— eco eae =e $. oe 2ieiastccwusews sea eee 0. 80 
Breadth of head just back of anterior rim......... Sa see de ont bees eee 0. 60 
Breadth of head, narrowest (constricted) part... ..22.. 0--. seceee enue cee noe on 0,31 
Breadth of first segments, widest (posterior) part .....-..-...-....-..--.--6-- 0.50 
Breadth of first segments, narrowest (anterior) part............---. 22.22.2200 0. 28 
Average length of segments, longer alternates .......-..------ s2..------ ----- 0. 35 
Average length of segments, shorter alternates........ -....-.-2- -----+ seseee 0. 24 
Breadth ot widest Seomenisn: 22. 5-5-2 ata ee wicca sacle see 0. 90 
Average length of widest segments -..-....-.----5 -eeees -- -- eee conn ne en ennes 0.12 
Width ‘of posterior segments. -. oo. o-oo ee es wee eee he coc s so tae ono eee 0.35 
hength of posteriorseements...22-- so-ceesss- 22-6 sem asoo= <== mee see 0. 36 
Habitat.—Both young and adult, one specimen of the former and six 
of the latter, were taken from the intestine of a spear-fish ( Tetrapturus 
albidus Poey), August 8, 1885, at Wood’s Holl, Mass. 
Dibothrium alutere, sp. nov. 
[Plate I, Figs. 5-8. ] 
Near Dibothrium microcephalum Rudolphi, Diesing, Systema Helminth., i, 592. 
Ibid., Sitzungsb., xiii, 578, Revis. Ceph., Par. 241. Wagener, Nov. Act. 
Nat. Cur., xxiv, Suppl., 16, 69, tab. vu, 77. Van Beneden, in Bullet. 
Acad. Belgique, xxii, ii, 521. 
Bothriocephalus microcephalus Bellingham, Ann. Nat. Hist., xiv, 253. (Habitat, 
Orthagoriscus mola. ) 
Head subsagittate with rounded apex; bothria oblong, lateral; neck, 
none; first joints distinct, about as long as wide, becoming much shorter 
and crowded together, much wider than long; genital apertures un- 
known. 
Habitat.—File Fish (Alutera Schepfii), Wood’s Holl, Mass., August, 
1884; 104 specimens from intestines of a single fish. 
_ These specimens were all immature, none of them had the genital 
apertures developed. They ranged in length from 20™™" to 94™™, The 
bothria in the smaller specimens are convex (Fig. 5), the central con. 
vex portions thin and transparent. A lateral view shows the bothria 
