COPEPOD PARASITES AND MUSSEL GLOCHIDIA ON FRESH-WATER FISHES. 367 



Behind the head the body narrows for a short distance, then widens gradually, and there is no abrupt 

 posterior enlargement. At the posterior end on either side above the base of the egg string is a small 

 tubercle which is single and does not project much from the body; the dorsal median tubercle, the 

 abdomen, is considerably larger than the lateral ones and terminates in the usual anal papillae. Each 

 egg string is half the length of the body and four-fifths the width and tapers posteriorly to a narrow 

 roiinded point; the eggs are minute and there are about 150 in a string. 



The head is circular in outline and a little wider than long; first antennsE three-jointed, joints 

 diminishing a little in length and diameter from the base outward and heavily armed with setae; second 

 antennae two- jointed, joints the same length, the tasal one imarmed, the terminal one with the usual 

 armature of stout curved claw and setse. Second maxillae as large as the maxillipeds, with stout ter- 

 minal claws; maxillipeds short and thickset, each with four terminal claws, a small knob at their base 

 and a minute process on the iimer margin. 



Color (preserved material), a grayish white. 



Body length (excluding the horns and egg strings), 9.60 mm.; greatest diameter, 0.60 mm.; trans- 

 verse length of botli horns and head, 5.66 mm. Length of egg strings, 4.25 mm. 



{tenuis, slender, alluding to the body as a whole.) 



Remarks. — This species may be recognized by the fact that its horns stand out at right angles to 

 the body axis and are cylindrical instead of flattened; its body is not enlarged posteriorly, and the egg 

 strings are very long and slender. It does not appear to be common, since only a single specimen has 

 thus far been found, and it is not known to be associated with any glochidium. 



Lemseocera cruciata Le Sueiu". (PI. Lxxm, fig. 108, 109; PI. lxxiv, fig. no.) 



LeriuEoc^a cruciata Le Sueur, 1S24. Jour. Acad. Nat. Sci. Philadelphia, vol. 3, p. 286, pi. 2; Kellicott, 18S0, Proc. Amer. 

 Soc. Microscopists, vol, i, p. 64. pi. 1, fig. i. 



Host and record of speciinens. — This species was originally reported by Le Sueur from the " rock bass 

 Cichla cenea" {Ambloplites rupestris) of Lake Erie. Kellicott's specimens were taken from "rock bass 

 in the Shiawassee River, the Upper Saginaw, at Corunna, Mich., about 25 per cent of the fish being 

 parasitized. * * * They are taken occasionally from the Niagara at Buffalo. " (p. 68.) Gurley in 

 his manuscript identified this species from the following hosts and localities: On rock bass from Lake 

 Erie at Erie, Pa., June 21, 1894; from the Sandusky River at Fremont, Ohio; and from Fox Creek (tribu- 

 tary of the Detroit River) at Detroit, Mich., the latter on August 22, 1894 (collector, Cloudsley Rutter). 

 On the sunfish, Eupomotis gibbosus, from Cattaraugus Creek (tributary of Lake Erie) at Gowanda, 

 N. Y., August 17, 1893; from Elk Creek, Girard County, Pa., August 3, 1893; and from the Maumee 

 River at Perrysburg, Ohio. On the redhorse, Moxostoma macrolepidotum duquesnei, from Maple River 

 in Cass County, N. Dak. Gurley adds: "It should fiulher be noted that the specimen in question is 

 clearly L. cruciata and not Kr0yer's L. oatostomi, which also infests the redhorse." 



Three lots of specimens were taken from the flesh along the sides of the body of the largemouth 

 black bass, Micropierus salmoides; 10 females from Black Creek, N. C. , catalogue no. 42306, U. S. National 

 Museum; 7 females from Crooked S Slew, Fairport, Iowa, catalogue no. 47728, U. S. National Museum; 

 5 females from Scott, Lonoke Coimty, Ark., catalogue no. 47729, U. S. National Museum. 



Specific characters of female. — Body club-shaped, rather slender toward the head, gradually increas- 

 ing in diameter posteriorly and terminating in a sudden enlargement at the posterior end. From either 

 side of the cephalothorax extends a stout horn , chitinous in texttu-e, which immediately divides into two 

 conical branches, one of which is tinned forward and the other backward at varying angles. The basal 

 portion of each horn is short and very broad, while the base of the posterior branch is often twice the 

 diameter of the anterior. Body obscurely segmented, with a large double tubercle on either side at 

 the posterior end, the median dorsal tubercle, the abdomen, being still larger though single and termi- 

 nating in two small anal papillae, each armed with two or three setae. Egg strings conical, the base 

 attached to the body, the pointed end free, one-third as wide as long; eggs small, not arranged in rows, 

 about 100 in each string. 



Head one-quarter wider than long, with a narrow rostrum projecting from the center of the anterior 

 margin; first antennae foiu-- jointed, the basal joint the shortest, the next joint the longest, all the joints 

 heavily armed with setae; second aatennae two-jointed, joints about the same length, the basal one 

 unarmed, the terminal one ending in two curved claws, two long setae and a shorter one, with fom- minute 

 spines along the inner margin. 



