COPEPOD PARASITES AND MUSSEI* GLOCHIDIA ON FRESH-WATER FISHES. 369 

 Lemseocera catostomi Kr0yer. 



LenuEocera catostomi Kr0yer, 1863, Naturhistorisk TidsskriJt, vol. 2, p. 321, pi. 18, fig. 4, a-c. 



Host and record of specimens. — Two females were found by Kr0yer upon a Moxosioma macrolepidoium 

 duquesnii from the Mississippi River near St. Louis, Mo. None have been found since and the original 

 specimens are probably lost, so that we are compelled to rely wholly upon Kr0yer's description and 

 figures, which may be summed up as follows: 



Specific characters of female. — Body long and club-shaped, enlarged two or three diameters posteri- 

 orly; a short horn on either side of the cephalothorax, flattened anteroposteriorly and cleft at the tip; 

 a similar median dorsal horn. Body segments indistinct; lateral tubercles at the posterior end poorly 

 defined, median dorsal tubercle, the abdomen, but little longer and comparatively wide; egg strings 

 narrow and elongate. 



Head circular in outline, with a small broadly obtuse rostrum on the anterior border; first antennae 

 three-jointed and heavily armed with setae; second antennae two-jointed, the basal joint long and linear, 

 the terminal joint small, oval, and armed with small setae and spines; maxillipeds with a swollen basal 

 joint and an oval terminal joint, tipped with four large and strong claws, gradually increasing in size, 

 the outermost one as long as the segment; knob at the base of these claws small, papilla on the inner 

 margin also small and tipped with a single spine. 



Color, a uniform whitish yellow. 



Body length (excluding horns and egg strings), 8 mm.; greatest diameter, 1.35 mm. 



Remarks. — Neither of Kr^yer's specimens had complete egg strings, so that their length can not 

 be given, but the remnant left on one of the females indicated that they were long and narrow and the 

 eggs were small. The species is readily distinguished from cruciata, which is found on the same host 

 by the fact that it has three horns instead of two. From tortua it may be distinguished by the smaller 

 size of the horns and the larger size of the abdomen and by the details of the antennae and maxillipeds. 



Lemseocera pomotidis Kr0yer. (PI. lxxiv, fig. 114-118.) 



LerncBocera potnotidis Kr0yer, 1863, Naturhistorisk Tidsskrift, vol. 2. p. 323, pi. 15, fig. 5, a-h. 



Host and record of specimens. — Six or seven females were originally obtained by Kjjryer from the gills 

 of a " Pomoiis" species near New Orleans. These are the types of the species and if extant are in the 

 Royal Museum at Copenhagen. A single female was taken from the gill cavity of the bluegill, Lepomis 

 pallidus, at Fairport, August 29, 1914. It has received catalogue no. 47773, U. S. National Museum, 

 and will serve as a surrogate type of the species if the original specimens are no longer in existence. 



Specific characters of the species. — Body long and slender, only slightly enlarged posteriorly; a horn 

 on either side of the cephalothorax, divided into two branches which are longer than those in cruciata, 

 more slender, and more nearly parallel with the long axis of the body; each horn is two-fifths the entire 

 length of the body and about the same diameter as the anterior portion of the thorax. Body obscurely 

 segmented, the lateral tubercles at the posterior end large, distinct, and with a slight emargination at 

 the center; the median dorsal tubercle, the abdomen, heart-shaped and but a trifle longer than the 

 lateral ones; egg strings narrow and elongate. 



Head circular in outline, about the same length and width and without any anterior rostrum; first 

 antenna four-jointed, the three terminal joints the same length and well armed with setae, the basal one 

 shorter and unarmed ; the terminal joint carries at its tip two cinved claws, similar to those on the second 

 antennae; the latter are two-jointed, the terminal joint considerably longer than the basal and more slen- 

 der; second maxillae small with slender terminal claws; maxillipeds also small and slender, two- jointed, 

 and terminating in three claws, with no knob at their base but with a large process on the inner margin, 

 tipped with a tiny spine; these maxillipeds do not quite reach the posterior border of the maxillae. 



Color a uniform creamy white. 



Total length (excluding horns and egg strings), 10.45 ™™-; greatest diameter, 0.50 mm.; length of 

 horns, 4.20 mm. 



Remarks. — This is undoubtedly the same as Kr0yer's specimens and shows that the species is not 

 confined to the lower part of the river nor to one host, but is likely to be found elsewhere. The present 

 host is one of the stmfishes and is closely related to Kr0yer's " Pomotis sp. , " and may even possibly be 

 identical with it. The species may be distinguished by the long, sharp, and slender horns and by the 

 fact that the body has almost no posterior enlargement. It is also worth special notice that it is found 

 on the gills or in the gill cavity and not on the outside of the body. It is not well enough known as 

 yet for it to be associated with any glochidium. 



