124 MR. H. CHARLTON BASTIAN'S MONOGRAPH 



Anus 5-^" from posterior extremity. Excretory duct oi^eniug opposite ocsopliageo- 

 intestinal junction (?). Lateral vessels straight, not convoluted. Vulva at commence- 

 ment of posterior third of body. 



Male, about same size as female. 



Amis jj-^" from posterior extremity. Sjncules solitary, large, curved, xirso'' long, 

 somewhat knobbed at upper extremities. 



Ilab. Found by Dr. Cobbold in the decaying pulp of pears '. 



11. CEPHALOBUS -, Bastian. 

 Gen. Chak. J3odi/ tapering slightly at extremities. Mead somewhat lobed. Caudal 

 sticker none. Integument having well-marked transverse strife ; no setae or papillee. 

 Pharyngeal cavity indistinct. Oesophagus 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 curved, somewhat fusiform. Accessory piiece posterior, median, easily re- 

 cognizable. Excretory ventral gland having a somcAvhat rigid, curved duct, opening 

 opposite posterior third of oesophagus. Lateral vessels straight; terminations un- 

 certain. 

 Movements sluggish. 



1. C. PERSEGNis, n. sp. (Plate X. figs. 104-lOG.) 



Female, length -^^", breadth 5-5-5". 



External Characters. — Body -white, tapering slightly anteriorly, and also posteriorly, 

 where it is blunt and rounded. Head bilobed. Striae transverse, distinct, tuoou" apart. 



CEsophagus between {-th and ^th of total length. Intestine slightly covered with a 

 few light-coloured hepatic particles. Anus 0-^5" from posterior extremity. Vulva at 

 posterior third of body. Excretory duct opposite narrowed portion of oesophagus. 



In his work on " Entozoa," Dr. Cobbold, speaking of Oxyuris vermicularix, remarks : — " Respecting; the migra- 

 tions of the larvae, I am not aware that anything very detinite is yet known. I have introduced the eggs containing 

 embryos into various animals, but have not yet succeeded in rearing young Oxyuridcs. 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 larvae to Leuckart, who thought they might be Anguillulce ; and certainly I never saw 

 the tadpole-like larvse, as such, out of their shells. The young Nematodes in question displayed a very different form. 

 As my experiments are 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 Pleetiis. 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 ; 

 but, after immersion in water for a few hours, I had no difficulty in verifying Dr. Cobbold's previous observations, and 

 recognizing the little Nematodes in full activity, showing that they also are endowed with the same property of re- 

 coverhig after desiccation as are the other species of these genera. Dr. Cobbold did not recognize two distinct 

 species ; and thinking all the animals found in the pear-pulp were individuals of the same species, he proposed for 

 it the name of AtiyniUuIa pyri, in a communication read before the last meeting of the BritishAssociation at Bath. 



■ Ke(j>ii\ii, the head, and Xo/jos, a lobe. 



