LEIDY'S DESCRIPTIONS OF AMERICAN WORMS. 49 



In both species of Enchytraeus the intervals of the body between the viscera and 

 integument are occupied by free, floating, granular, lenticular corpuscles, (fig. 15;) 

 each possessing a minute nucleus. The same kind of corpuscles exist in 

 many other worms, entozoa,* etc., and may probably serve the same purpose as the 

 blood corpuscle, although they are not their homologues. 



Both species of Enchytraeus are infested with a species of Leucophrys, (figs. 17a, b,) 

 occasionally in large numbers. From the ruptured integument of E. socialis, 

 I saw, in several instances, several hundred issue. It is hemi-elliptical in outline, 

 measures l-300th in. long by 1-lOOOth in. broad, and is probably the same species 

 as that found in Lumhricus terrestris. It is frequently observed in all stages of 

 division, the resulting individuals measuring one-half the length of the full grown. 



LuMBRicuLUS, Gruhy.-\ — Corpus quasi teres, hyalinum, acicularum geminarum 

 seriebus 4 armatum. Intestinum rectum, per totum fere longitudinem sacculis 

 digitatis, vas dorsale ramis amplis, contractilibus iis respondentibus, dilatatum. 

 Cinffulum nullum. 



O' 



8. LuMBRicuLus LiMosus. Fig. 16. — Body nearly cylindrical, acute anteriorly, 

 pretty uniform posteriorly ; color yellowish, translucent, with the dorsal and ventral 

 vessel presenting a rich scarlet hue ; the anterior five or six articulations bordered by 

 bluish black, central part of the body iridescent blueish. From one hundred and 

 seventy to two hundred and twenty four articulations. Girdle none. Ninth 

 articulation v/ith two perforations. Generative apparatus extending as far back as 

 the twentieth articulation. Podal spines in four rows, two in each fasciculus, 

 of a long sigmoid form, becoming abruptly narrowed at the distal extremity and 

 terminating in a double unguis, 1-145 in. long. Upper lip triangular, l-40th in. long 

 from the mouth, which latter is round. Gizzard none. 



Length from two to four inches, breadth two-fifths of a line. 



Habitation and Remarks. — This beautiful and very active worm is found under 

 stones, dead leaves, and fragments of wood on the muddy borders of creeks and 

 rivulets around Philadelphia. It undoubtedly belongs to the genus characterized by 

 Gruby, but is much longer than the Lumbriculus variegatus., Gruby. It exhibits 

 the same regular maculations in each articulation, mentioned by GrubyJ, dependant 

 upon lateral coecal diverticula of the blood vessels. I counted as many as fifteen of 

 these alternately dilating and contracting vascular coeca, on each side of an 

 articulation. The podal spines (fig. 16, a.) are of the same form as those depicted 

 by Gruby in the Archiv fur Naturgeschichte, Tab. vii. fig. 2, c. A little distance 

 from the origin of each pair of podal spines, there is always to be found a pair of 



• Miiller, Zoolog. Dan. V. ii. p. 39. Echiyiorynchus anguilla. " Vagina totum corpus occupans corpusculis 



linearibus, ovalibuS; et suborbicularibus repleta est." 



t Arch. f. Naturg. 1844. B. 1, S. 211. I Ibid. S. 208. 



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