NO. 2012. A NEW NEMATODE FROM THE COYOTE— HALL. 77 



R. splendida) between the two latere- ventral rows of spines, of which 

 he saw only the upper and nearer row. 



In the second place, Frolich and Dujardin state that the row of 

 spines extends from the head to the vulva, but Frolich adds that 

 rarely one notices one or more teeth behind the vulva. In this con- 

 nection it may be noted that the species of the genus Rictularia break 

 rather naturally into two groups, (1) those parasitic in carnivores 

 and in which the comblike cuticular structures of the anterior 

 portion of the body of the female change very gradually into the 

 spinelike structures of the posterior portion of the body, with no 

 noticeable alteration taking place in the immediate vicinity of the 

 vulva, and (2) those parasitic in rodents, insectivores, and bats, and 

 in which the comblike structures anterior of the vulva become 

 spinelike posterior of it, the transition being more or less marked in 

 the vicinity of the vulva. The comblike structures are larger, 

 continuous, and much more conspicuous; the spmelike are smaller, 

 separated, often widely so, and in some cases very inconspicuous. 

 The species which FroHch and Dujardin had, R. cristata, was collected 

 from rodents, Mus sylvaticus, Myoxus glis, M. nitedula, and M. 

 avellanarius, and probably followed the rule for rodent species that 

 the prominent combs anterior of the vulva were followed by incon- 

 spicuous spines posterior of it. Frolich's reference to the rare 

 occurrence of teeth behind the vulva bears out this assumption. 

 The writer feels safe, therefore, in adhering to a generic diagnosis of 

 Rictularia in which two rows of ventral combs or spines is specified, 

 even with a type-species described as having only one, on the ground 

 that there is ample reason and evidence for believing that the type- 

 species must have had two. I venture to think that a reexamination 

 of the type or other adequate material will confirm this opinion. 



So far species of this genus have been recorded only from the 

 small intestine, and this is the only habitat mentioned in the generic 

 diagnosis. However, I have collected a female Rictularia from the 

 stomach of a rodent on one occasion. 



RICTULARIA SPLENDIDA Hall, 1913. 



Specific diagnosis. — Rictularia: Close to R. cahirensis Jagerskiold 

 from Felis domestica (Egypt), and to R. affinis Jagerskiold from Felis 

 domestica and Vulpes vulpes niloticus (Egypt). As there seems to 

 be little of specific value that is common to both males and females, 

 the two will be considered separately. 



Male. — Length, 4.83 mm.; the maximum width, exclusive of spines, 

 in posterior part of body, 280 ;/. Dorso-ventral head diameter at the 

 base of the buccal capsule, 72 ^. Length of esophagus, L75 mm. 

 Nerve ring not discernable; 108 or 109 combs, attaining a height of 



