162 PROCEEDINGS OF THE NATIONAL MUSEUM. ■ vol. 50. 



This species is described by von Linstow (1878& and 1879«) as 

 Strongylus yoly gyrus Dujardin, but unless the figures of other spe- 

 cies are misleading in conveying the idea that there is one branching 

 dorsal ray, or unless von Linstow has erred in figuring his material 

 as having two dorsal rays and in stating that the vulva is anterior, 

 we are bound to conclude that von Linstow's species is not even con- 

 generic with Dujardin's. On the available evidence, I have regarded 

 his species as new and erected a new genus for it. His terminology 

 in regard to the female genitalia is not in accordance Avith present- 

 day terminology and I have altered it accordingly in the above 

 diagnosis. He also makes the statement that the spherical body an- 

 terior of the uterus is composed of unicellular glands which empty 

 their secretion into the lumen. While this may be correct, it might 

 also be noted that a somevrhat spherical muscular structure is a 

 common feature of the ends of theovijectors. 



Family METASTKONGYLIDAE Leiper, 1908. 



Family diagnosis. — Strongyloidea (p. 106) : Polymyarian. Buccal 

 capsule present or absent. Bursa present or absent; when present, 

 frequently atypical in structure and number of rays. Oviparous, 

 with eggs in variable stages of segmentation when oviposited, or 

 viviparous. Embryo not rhabditiform. Usually in respiratory and 

 circulatory systems, rarely in digestive system. 



Type-genus. — M etastrongylus Molin, 1861a. 



ANALYTICAL KEY TO SUBFAMILIES OF METASTRONGYLIDAE. 



1. Buccal capsule absent Metastrongylinae, p. 162. 



Buccal capsule present 2. 



2. Bursa much reduced or lacking; when present, with few and atypical rays. 



Two ovaries Rictulariinae, p. 168. 



Bursa well developed, with typical rays. One ovary Ollulaninae, p. 177. 



SuTafamily M:EJTASTROISrG-YLIN".A.E; Leiper, 19 OS. 



Subfamily diagnosis. — ^Metastrongylidae (p. 162) : Buccal capsule 

 absent. Male with two equal spicules and female with two ovaries. 

 Eggs in varying stages of development when oviposited. Embryo 

 not rhabditiform. Parasitic in the respiratory and circulatory 

 systems. 



Type-genus. — M etastrongylus Molin, 1861a. 



The life history in this group is not as yet very well ascertained. 

 Eomanovitch and Slavine (1914) state that when eggs of Dictyocaidus 

 filaria are placed in water, embryos form, two ecd^'ses follow, the 

 cuticle being retained, and that such encapsuled larvae produce 



