310 ORDER ANAXONCHIA 



to a considerable extent protrusile, just as in Eurystoma. The males of Bol- 

 MqthllOl bella seem to be considerably less common than 

 the females. 



Habitat: Sand, Bathing Beach, Woods Hole, 

 Mass., U. S. A. Flemming to glycerine jelly. 

 . Sublimate to balsam. Resembles Symplocos- 

 toma Bastian, but differs materially in the 

 structure of the posterior part of the oesoph- 

 agus, as well as in the absence of eye-spots. 

 The males of Symplocostoma have no sup- 

 plements. 



The strongly tapering neck of Bolbella results 

 in a head of small size. Notwithstanding its 

 small size, one is immediately struck by its 

 strong resemblance to the head of Eurystoma. 

 The following differences, however, are to be 

 ^m siilm dxt noted. The amphid is smaller and of a differ- 

 ent form, though here also, as in Eurystoma, 

 /V/ located on the dorsal side of the lateral lines. 

 While the pharynx is divided into two more or 

 xlSOO less distinct chambers, the division line is not 

 marked by transverse rows of denticles. Fig. 90a, p. 309; Fig. 906. 



91. Thoonchus ferox n. sp. Striae resolvable with difficulty. The thin, color- 

 less lips are arched over the pharynx as in Oncholaimus, but the minute flaps 

 often seen on the tips of the lips of Oncholaimus 



appear to be absent in this species, or at any ^ ^ '-^ 5^_ >2 .2.. 



rate, much reduced. Labial papillae located in 



the midst of shallow depressions. Amphids faint. ii| -| ^ """ 6 7 ^ 9 ^>2.i.. 



Pharynx denticulate. The oesophagus has the 



same diameter throughout its anterior half, after which it begins slowly to expand 

 and finally is two-thirds as wide as the base of the neck. There is a distinct, 

 bluntly convex-conoid cardia, nearly half as wide as the base of the neck. The 

 intestine, which is separated from the oesophagus by a deep constriction, becomes 

 at once three-fourths as wide as the body. It is rather thin walled and in cross 

 section presents about six cells. These cells contain scattered, yellowish gran- 

 ules of variable sizes, so arranged as to give rise to an obscure tessellated effect. 

 The largest granules have a diameter nearly equal to the thickness of the body 

 wall. Posterior lip of the anus strongly elevated. Rectum equal in length to 

 the anal body-diameter. Renette elongated, located a little distance behind 

 the cardia. The lateral fields appear to be rather narrow; they are character- 

 ized by the presence in them of numerous, rather scattered, yellowish granules, 

 which are more numerous toward the edges of the field, and which, therefore, 

 define the fields more distinctly than is usually the case. At the base of the 

 head, the fields are seen to widen out and terminate in a rounded contour; the 

 margin of this contour marks the position of the amphids. The granules found 

 along the lateral fields appear also in longitudinal rows outside these fields. 

 Thus, on either side of the lateral fields, there is a single distinct row of these 

 granules; on the submedian line, another very distinct assemblage of granules, 

 consisting of several irregular rows. Then comes another scattered faint row; 

 then a ventral or sub-ventral assemblage consisting of several rows. There is 

 thus produced on the neck as well as elsewhere quite a distinct longitudinal 



