433] PSEU DOPEY LLIDEA FROM FISHES— COOPER 145 



to be glandular in nature, altho muscle fibres traverse the mass in several direc- 

 tions, the inner of them being longitudinal and the outer circularly oblique. 

 Altho this structure may have a glandidar function in connection with the 

 passage of the eggs to tlie exterior, it obviously acts as a powerful sphincter 

 controlling the same and permitting perhaps of the laying of only a few at a 

 time. Distal to the outer end of the funnel, where it loses these fibres, the 

 sac continues through the cortical parenchyma as a narrow tube to the pore. 



The eggs of this species were said by Linton (1889 and 1890) to be of two 

 kinds: "... one yellowish in mounted specimens with a strong shell, in some 

 cases white and opaque; another sort transparent, with a very thin shell." 

 These differences were seen in the material studied, but they were considered 

 to be merely due to differences of age, the thinner-shelled ones being the 

 younger. While the same author gave the length and breadth as 45 to 54/t 

 and 27 to 30ju, respectively, the writer found their maximum dimensions to be 

 in sections 58 by 34/z. 



The material studied consisted of two lots: No. 4711, in the collection of 

 the United States National Museum, from the rectum of Tetrapteriis sp. from 

 Penekese, determined by Linton; and No. 16.461 in the collection of the 

 University of Illinois, from the intestine of Histiophoriis gladius, obtained from 

 Prof. Linton, and evidently the actual specimen described by him in 1890. 

 The details of the anatomy, here given, were studied from confirmatory sec- 

 tions of the latter. 



DIBOTHRIUM LACINIATUM Linton 



Linton (1898:425) established this species on the basis of the material 

 contained in lot No. 4741 of the collection of the United States Museum from 

 Tarpon atlanticus, and again reported it from the same host species in 1901 

 (p. 437). Liihe (1899:43) in his list of the species of the genus Bothriocephalus 

 s. str. remarked that "Von weniger gut bekannten Arten gehoren anscheinend 

 noch hierher Bothriocephalus laciniatus (Lint.) und occidentalis (Lint.);" while 

 Ariola (1900:414) also placed it in the same genus, as he conceived the latter 

 to be constituted. 



During the study of B. mamibriformis the writer was impressed with the 

 great resemblance between D. lacimatum and it, in all but a few details, the 

 two being, in fact, identical. The measurements for length and maximum 

 breadth, as shown in the comparative table below, agree, while those of the 

 scolex and anterior segments are as near as can be expected from cestode 

 material which is found in various degrees of contraction and relaxation. All 

 of the conditions represented in Linton's (1898) Figs. 7 to 12, PI. XXX, were 

 observed in the material of B. mamibriformis studied — when such obvious 

 errors as, "Fossettes marginal as to head, corresponding to the flat surface of 

 the body, " are taken into consideration — while the description of the external 

 features, excepting that of the posterior segments, applied in detail. But 

 later lot No. 4741, U.S.N.M., was obtained by Professor Ward, and the WTiter 



