254 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 13, No. 12 
ZOOLOGY.—WNotes on Paratylenchus, a genus of nemas. N. A. 
Coss. U.S. Department of Agriculture. 
The following paragraphs contain new information with regard 
to the lip region, vestibule, spear guide, structure of the spear, median 
bulb, salivary glands, deirids (cervical papillae), renette, eggs and 
their deposition, and gonism of Paratylenchus Micoletzky 1922. 
82 18.24, 2-82. 95.8 
© S al - 0.41 mm 
Paratylenchus nanus n. sp. 3-7 4:3 7 45 4,2 2. The trans- 
parent, colorless, naked cuticle, about 1.5 microns thick, is traversed by plain, 
transverse striae, 2.0 microns apart except near the extremities, all alike and 
fairly easy of resolution, which are materially altered on the lateral fields by 
the presence of wing regions, about one-seventh as wide as the body, beginning 
on the neck and ending on the tail. The optical expression of the wings on 
living specimens usually consists in four parallel longitudinal lines on each 
lateral field, the two outer of which are fainter than the two inner. Very 
slightly oblique longitudinal striae of the subcuticle, all alike, due to the 
attachment of the musculature, are rather easily to be seen in nearly all regions 
of the body. The contour of the body is crenate or very faintly serrate- 
crenate. There are no dermal appendages and there are no series of pores to 
be seen in the cuticle. On the neck opposite the excretory pore, lat. 22.2,* 
there is a papilla on each lateral line, and, leading inward, ventrad and slightly 
backward from the middle of each papilla is an obscurely sinuous element 
connecting with the nervous system. These two organs are therefore believed 
to be deirids (‘cervical papillae’’). 
The neck, which is cylindroid posteriorly, and to a considerable extent also 
anteriorly, becomes decidedly convex-conoid farther forward, and ends in a 
rounded or subtruncate, continuous head compassing about thirty annules 
of the cuticle, which presents a somewhat depressed, very minute, central 
mouth opening, closely surrounded by szx equal, exceedingly minute lips. The 
truncation of the head occurs at the lip region, which has at this point, that is 
at the anterior extremity of the nema, a width of about two microns. The lip 
region is supported by a faintly visible six-ribbed, refractive, somewhat dome- 
shaped, cuticular framework, six to seven microns across at the base, and 
about two-thirds as ‘“‘high” as it is wide. The more or less immobile lips are 
usually closed. 
*The Word “‘Latitude” in Descriptive Nematology. I have lately come to use the 
word “‘latitude” in a conventional sense in dealing with nema anatomy, and find it so 
useful as to lead to this attempt more accurately to define the word as thus used. 
The meaning of latitude in this connection arises from geographical usage, but in 
nematology the term applies to a transverse plane or section of the organism, and not to 
a circle on the surface only, as in geography, and it has not seemed desirable to have two 
sorts of latitude, such as north and south. 
One hundred degrees of latitude is assumed, with zero at the anterior extremity of 
the organism. Thus an element of the organism in latitude 50 would be at the middle; 
and in latitude 100 at the end of the tail. The terms can be abbreviated as in geography 
so as to be short and specific. Thus: lat. 60. 
In the case of nemas, which are so nearly round in cross section, a similar use of the 
word “longitude” sometimes becomes useful, the ventral line being taken as the zero 
line, the dorsal line thus becoming 180. 
The conventional use of the words latitude and longitude in this way is more or less 
“logical”, and very easily acquired, and, according to my experience, is a decided saving 
in time and space, and has the merit of definiteness, as well as brevity. 
