ECLIPIDRILIDvE AND THEIR ANATOMY. 



ECLIPIDRILUS FRIGIDUS n. sp. 



Vascular system. The dorsal and ventral longitudinal vessels are 

 of nearly the same size, the former only is pulsating. The ventral vessel 

 is forked in the first setigerous segment of the body, the dorsal vessel 

 is entire, connecting with the two forks of the ventral vessel in the ce- 

 phalic lobe (PL I. fig. 2. D. v. & v.v.) 



The secondary or lateral vessels are of two kinds viz.: 



a. perigastric^ situated in the perigastric cavity of the body, and 



b. (jastric, situated on or close to the alimentary canal. 

 The perigastric vessels are of two kinds, viz. : 



1. Connecting perigastric vessels, and 



2. free perigastric vessels. 



The connecting perigastric vessels are found in the anterior seg- 

 ments of the body, connecting the two principal longitudinal vessels. 

 One pair is found in the buccalic-segment and one pair each in the nine 

 first setigerous segments. (PI. I. fig. 2. p. v.). The two last connecting 

 ■perigastric vessels, originating respectively in the 8"" & 9"' setigerous seg- 

 ments, are considerably longer than the rest and furnish blood both to 

 the generative and copulative organs. They are also not confined to 

 their respective segments but extend considerably backwards, sometimes 

 as far as to the lO"* or 14"' segment. The anterior pair is the shortest, 

 and extends only to the 10"* segment, while the pair originating in the 9"* 

 segment extends as far back as the H"* segment or as far as the sexual 

 organs reach. In the 10"" and following posterior segments, no connecting 

 perigastric vessels are found. None of these connecting perigastric vessels 

 are dilated to hearts, but all are slightly pulsating, the anterior ones 

 more so than the posterior ones (fig. 2). 



The free perigastric vessels are dorsal and found in the 30 odd 

 posterior segments, two pair in every segment, emitted from the pulsat- 

 ing dorsal vessel, and also themselves slightly pulsating. As to the form, 

 they are short, thick, and all more or less imperfectly forked or branched. 

 Their inner end is free, and does not connect with the ventral vessel, 

 (PI. I. fig. 3. pv.). 



Of the gastric vessels one pair is found in every segment, which 

 does not contain any perigastric vessels: The gastric vessels run along 

 side the alimentary canal and connect the ventral and dorsal longitudinal 



