790 LAIIVAL CESTODJ: PARASITES OF FISHES— LINTON. vol.xix. 



on the neck. Its diuieusious, living, were : Length, 0.45 mm. ; breadth, 

 0.08: length of bothria, 0.1; breadth of head, 0.12. 



In addition to those found infesting the cystic duct, others were found 

 in the intestine of some of the lish examined. Of these there were two, 

 types, as in those of the cystic duct. 



First type with a costa on each bothriuni, the bothria long elliptical,' 

 body slender, ])roboscis (rayzorhynchus) very extensible, cylindrical, 

 with small round shallow mouth. Second tyjie larger, stouter, with two 

 distinct red blotches back of the bothria, no costae on bothria, or with 

 only a faint indication of a costa on the anterior part, proboscis (myzo- 

 rhynchus) round elliptical, extensible campanulate, often maintained in 

 a comparatively rigid position with flaring bell-shape<l or vase-shaped 

 border widely ojien at the ai)ex. When at rest, the body is invaginated 

 and often contracts until it is oval or sometimes almost circular in out- 

 line. When this is the case, transverse wrinkles are apt to form on the 

 posterior part of the body. 



The specimens in the intestines were much snuiller, as a rule, than 

 those in the cystic duct. 



They were iound in myriads (Xo. 4780, U.S.N.M.) in a squeteague 

 examined on August 18, 188G, in the chyle and adhering to the mucous 

 membrane of the intestine. When extended until the body was quite 

 filiform, they were as much as 2.1 mm. in length; when contracted and 

 the h^d involuted, they became as short as 0,35 nun. and nearly cir- 

 cular in outline. Posterior edges of bothria free. 



^Measurements of three specimens Avere made with the following- 

 results, given in millimeters: First specimen, length, 0.45, breadth, 

 0.28; second specimen, length, 0.84, breadth, 0.17; third specimen, 

 length, 1.05, breadth, 0.12. When these specimens are compared with 

 respect to their superficial areas, it will be seen that they may be rep 

 resented by the numbers 12(5, 142, and 1-0 respectively. Indeed dimen- 

 sions corresponding to those of the first and third specimens might 

 have been obtained without difticulty from a single living and actively 

 contracting specimen. 



Length of bothria about 0.14 mm.; breadth, 0.07 to 0.1. 



Body with many highly retractile oval masses. 



The primary host, or hosts, of these larva' will doubtless be found 

 among the various species of crabs which inhabit the feeding grounds 

 of the scjueteague and flounder. Forms resembling them have been 

 figured by Beneden from Carcinus and rayitnis (Les Vers Cestoides, 

 Plate I, figures 10-14), as well as from various species of fish. Wag- 

 ener (Entwickelung der Cestoden, Plate 0, fig. 10 etc.) also figures 

 forms which bear a general resemblance. The latter, however, are all 

 from piscine hosts. 



2. Larvae from intestine of sand-dab {Liman<h< /(rnajinea) (No. 4814, 

 U.S.X.:^L), Woods IIoll, Massachusetts, September 6, 1887. 



Alcoholic specimens 2 to 2.5 mm. in length. These agree closely with 

 some of Beneden's figures of scoleces from Ixlionihus {Cestodes, Plate I). 



