124 MR. H. CHARLTON BASTIAN’S MONOGRAPH 
Anus sls" from "posterior extremity. Æreretory duct opening opposite cesophageo. 
intestinal junction (?). Lateral vessels straight, not convoluted. Vulva at commence. 
ment of posterior third of body. 
Male, about same size as female. 
Anus sts from posterior extremity. Spicules solitary, large, curved, 150 long, 
somewhat knobbed at upper extremities. 
Hab. Found by Dr. Cobbold in the decaying pulp of pears !. 
11. CEPHALOBUS Y, Bastian. 
Gen. CHAR. Body tapering slightly at extremities. Head somewhat lobed. Caudal 
sucker none. Integument having well-marked transverse striæ ; no setze or papillæ, 
Pharyngeal cavity indistinct. Œsophagus narrowed previously to its termination 
in a rounded swelling containing a simple valvular apparatus. Intestine sparingly 
covered with light-coloured fat-particles; intestinal tube proper easily seen. Vulva 
at commencement of posterior third of body. Uterus unsymmetrical. „Spicules 
slightly eurved, somewhat fusiform. Accessory piece posterior, median, easily re- 
cognizable. Exeretory ventral gland having a somewhat rigid, curved duct, opening 
opposite posterior third of cesophagus. Lateral vessels straight; terminations un- 
certain. 
Movements sluggish. 
1. C. PERSEGNIS, n.sp. (Plate X. figs. 104-106.) 
Female, length 4”, breadth 41". 
External Characters.—Body white, tapering slightly anteriorly, and also posteriorly, 
where it is blunt and rounded. Head bilobed. Striæ transverse, distinct, -5455° apart. 
Œsophagus between {th and lth of total length. Intestine slightly covered with a 
few light-coloured hepatie particles. Anus ais’ fiu posterior extremity. Vulva at 
posterior third of body. Exweretory duct opposite narrowed portion of cesophagus. 
1 In his work on “ Entozoa," Dr. Cobbold, speaking of Ozyuris vermicularis, remarks :—“ Respecting the migra- 
tions of the larvæ, I am not aware that anything very definite is yet known. I have introduced the eggs containing 
embryos into various animals, but have not yet succeeded in rearing young Oxyurides. I have also introduced them 
into the pulpy parenchyma of pears; but I have not been able to satisfy myself that any of the young Nematodes 
which I subsequently procured, by thousands, in one or two of the pears were the result of these experiments. I 
showed some of these living larvæ to Leuckart, who thought they might be Anguillulæ ; and certainly I never saw 
the — larvæ, as such, out of their shells. The young Nematodes in question displayed à very differerit form. 
As my ST UNS iens in the act of being repeated, I will now say no more on this head” (pp. 369, 370). 
\ I am indebted to the kindness of Dr. Cobbold for the opportunity of examining these animals, when I at once recog- 
nized two distinct species, belonging respectively to the genera Aphelenchus and Plectus. The representatives of the 
former genus, constituting the species above described, were by far the most numerous, though those of the genus 
Plectus were larger and much more active in their movements, The portion of pear-pulp sent to me was quite dry; 
E — nn in water for a few hours, I had no difficulty in verifying Dr. Cobbold’s previous observations, and 
MEER 2 mile Nematodes in full activity, showing that they also are endowed with the same property s 
udi "n dS as mO other species of these genera. Dr. Cobbold did not recognize two yer 
nn. pee the animals found in the pear-pulp were individuals of the same species, he proposed 
s : 4 pyrt, m a communication read before the last meeting of the BritishAssociation at Bath. 
xehaA, the head, and Aoßos, a lobe, 
