PARASITES OF FISHES OF THE WOODS HOLE REGION. 483 



than in the forms upon which that species was based. No spines were noted, Iiut tlie body was 

 crossed l)y fine transverse stri;e. Dimensions of living specimen in milHraeters: Length, 1.19; 

 diameter, anteriorO.OS, middle 0.23, of oral sucker 0.07, of acetabulum 0.07; ova, 0.052 and 0.034 in the 

 two principal diameters. Spherical bodie.s were noted in the excretory vessels. Associated with this 

 distome were two smaller, oval, minutely spinose distomes. Dimensions, life, in millimeters: Length, 

 0.73; diameter, anterior 0.1, middle 0.34, of anterior sucker 0.07, acetabulum 0.08; ova, 0.065 and 

 0.04 mm. in the two principal diameters; diameter of spherical liodies, 0.02. An immature distome 

 collected August 30 probably belongs to this species (fig. 345). Some of these small oval distomes 

 resemble D. jii/rifitrmi'. 



22. Diftomum dfiitatum Linton. Intestine. 7, pp. 283, 294, pi. x.xxix, figs. 64-67. 



Found on seven different dates in 1899. July 26, 1900, adults with ova, smaller without; the 

 young were relatively much more slender than the adults. August 9. 1900; numerous. August 10, 1900; 

 about 12, large and small. The following note was made at the time of collecting the specimens referred 

 to this species on August 9: Younger specimens translucent, bluish, older specimens yellowish. A few 

 of the older ones without spines thought at first to l)e different species. Seen by making comi)arative 

 measurements to be the same excejit for the matter of spines, and that the ova in the si)ineless ones 

 seemed to be a little larger. Either these siiineless forms will prove to belong to some species like 

 D. ritrllufni.ia or D. slmidcr or they will have to l)e regarded a-^ examples of TK dcidiiluni which have 

 lost not only the large spines from the mouth, but the smaller spines from the body as well. A 

 reexamination of these si)ecimeus leads me to conclude that those which do not have the spines around 

 the mouth belong to this species. The oral spines are evidently lost in the older worms. Three 

 distonies collected August 14, 1899, were thought at first to belong to a different species, on account of 

 what appeared to be a peculiarity in the structure of the oral spines. The.se appeared to be directed 

 forward and to he hastate in shape. This appearance was later found to be due to the fact that the 

 (iral sucker was everted to such an extent as to bring the bases of the spines in focus first. The only 

 important differences observable l>etween these specimens and the D. (leiilnliini as originally described 

 is that the opening of theacetalmlum is round instead of transverse, anil the pharynx jnTiform, broader 

 than long, in alcoholic specimens, but such characters should be given little weight in the determination 

 of distomes. The folUiwing measurements are given for the purpose of comparison with those given 

 in the description of the species. Dimensions of living specimen in millimeters: Length, 2.86; diameter 

 at anterior sucker 0.29, at acetabulum 0.76, middle 0.75, i^osterior 0.42; oral sucker, length 0.24, 

 breadth 0.24; acetabulum, length 0.23, breadth 0.24; pharynx, length 0.19, breadth 0.18; length of 

 oral spines, longer 0.03, shoi'ter 0.02; length of body spines, 0.017; ova, 0.079 and 0.041 in the two 

 prini'ipal diameters. Dimensions of alcoholic specimen in millimeters: Length, 2.03; transverse 

 diameter of oral .sucker 0.17, of acetabulum 0.2; jiharynx, length 0.1, breadth 0.16; ova, length from 

 0.055 to 0.072, breadth ().03S to 0.041; anterior border of acetal)ulum0.5 from anterior end. The distcmie 

 noted in 7, p. 296, pi. xl, figs. 73-75, may lie a specimen of D. di'iilalnin which has lost the ural spines. 



HHVN(II01!J)ELMD.\. 



23. I,i(rh. From luduth. Tliis is pn >bably a young specimen of I'miitilnlilld rd/iii.r ^"errilI. See under 



.S'toiotoHMis, No. 14. 

 The sijecimen was red when first seen. After lying oveiiiight in water it became yellowish 

 green, and when put in Gilson's meeuro-nitric solution changed to a decided grass-green. July 24, 

 1899. Dimensions in millimeters, alcoholic: Length, 8.25; diameter (maximum) of body 0.42, of 

 posterior sucker 0,57, of anterior sucker 0.42, of neck 0.28. 



Paralichthys oblongus, Fonr-Kpatteil Flouniler. 



FOOD. 



Auiiust 5, 1899; 4. Taken in the trawl in about 30 fathoms of water off Gay Head: Shrimps, 

 amiihipiids, and nther small crustaceans, annelids, a small lamellibranch mollusk, shell of I'lrtridus 

 caiKiliciihdus, and anothei' univalve shell with a worm tube on it in alimentary tracts. .\ug. 16. 1899; 4. 

 Large numbers of amphijiods, shrimps, etc., a few small crabs, and small fish in alimentary tracts. 

 August 2, 1900; 4. Taken in iluskeget Channel. Small crabs (Cancer) and shrimps in stomach. 



AC.VNTIIOlEI>H-\L.\. 



1. Echinorhi/nchux aenn Rudolphi. Intestine. Aug. 16, 1899; 1. See 3, ji. 525, etc 



