180 REPORTS ON THE STATE OF SCIENCE.—1912, 
(Auriv.) was universally present on the baleen-plates of the ‘ Blue 
whale.’ No other external parasites were found on this species. 
B. Internal. 
1. B. musculus (.).—In the individual labelled No. 13 in Table I. 
a small number of worm-like animals were found. They were attached 
by’ one end to the mucous membrane of the second chamber of the 
stomach, which contained no food. They were about 14 inch long, and 
only four were found. These are certainly Echinorhynchi, but the 
exact species has not yet been determined. The presence of Echino. 
rhynchi in the stomach of this species does not seem to have been 
recorded until now. 
In one individual [No. 12, Table I.] about half a dozen small oval 
white bodies were found very loosely attached to the wall of the intes- 
tine. These have been identified as the Trematode Monostomum 
plicatum (Creplin).** Their anatomy has been fully worked out by 
L. A. Jagerskiold.** They are about 6 mm. long and 3 mm. broad. 
The most interesting thing about them is that they have longitudinal 
striations on the under-surface, which no doubt help them in attach- 
ing themselves to the mucous membrane of the intestine. Creplin 
fancifully compares these. striations to the throat-grooves of the whale. 
2. B. sibbaldii (Gray).—The intestines of individuals of this species 
often contained large numbers of an Echinorhynchus, which has been 
identified as Hchinorhynchus brevicollis (Malm).4° No other internal 
parasites were found. 
XV. PROBLEMATICAL ORGANS. 
In Balenoptera musculus, just inside the tip of the lower jaw, over 
the symphysis, were noticed two small openings, each partly covered by 
a small valve-lhke flap. The skin just around these openings and on the 
valve-flap was yellowish white. The openings were about 2 inch apart, 
and they lead into a small canal, which soon branches into three or four. 
The longest of these extends backwards and slightly downwards, and 
is about 1 inch in length. 
In the case of B. stbbaldti each spot marked the position of the open- 
ings of about four very narrow canals, each of which was about 1 inch 
in length. These openings in each species appear to be quite constant 
in form and position. In both cases the outer integument appears to 
be tucked in for the whole course of the tubes. In one preparation there 
appeared to be some mucus-like substance in the tube, but no structures 
comparable to glands opening into the tubes could be discovered. On 
account of the very tough connective.tissue around the symphysis of the 
lower jaw, the portions with these canals are very difficult to work with 
in cutting sections. 
The function of these organs is quite obscure, and I can find no 
43 Creplin, Nov. Act. Acad. N.C.,-xiv., p. 873. 
44 Jagerskiold, Kgl. Svenska. Vitensk. Akad. Handlinger, Bd. 24, No. 7, 
1891 (called here Ogmogaster plicatus). 
** Malm, ‘ Monogr. Illustr. Balenopt. . . . cdte occ. de Suade,’ fol., Stock- 
holm, 1867. : : 
