1911] MicJiacI: Clinetognatha of the San Diego Region. 31 



translucent, nearly transparent appearance. The general color 

 of the body is grayish-white while the tip of the tail, ovaries, 

 intestine, ventral ganglion, and head are much more opaque 

 (pi. 1, tig. 2). When well-developed the seminal vesicles also 

 offer a decided contrast to the body proper. The fins are readily 

 seen, appearing as very transparent areas. 



Characters 



Bod}^ tumid, but not always retaining its form. Neck fairly evident 

 though not so pronounced as in S. enflata. Body widest at a point from 

 35 to 45 per cent of the total length behind the head. Lateral fields 

 large. Muscles weak and thin, but stronger than in S. enflata. They are 

 barely perceptible to the naked eye. Slight constriction at tail-septum. 

 Collarette absent. 



Anterior fin shorter and narrower than posterior fin. Never extends 

 to ventral ganglion, the distance from the ganglion being at least equal 

 to the length of the fin. Position of greatest width approximately cen- 

 tral. Form of fin half-elliptical. 



Posterior fin always extends more than half the distance from tail- 

 septum to seminal vesicles, but never reaches them. More than 50 

 (usually about 60) per cent of fin in front of tail-se^jtum. Position of 

 greatest width almost uniformly opposite tail-septum. Broadly trian- 

 gular in form. Interval from anterior to posterior fin usually less than 

 the length of anterior fin. 



Vestibular ridge (pi. 3. fig. 15) without the usual skeletal structures 

 and composed entirely of a few irregular conical papillae. They appar- 

 ently alternate in position with the few teeth that may be present. They 

 are broader and much shorter than the teeth. Sometimes there is a 

 double row of papillae present, presumably in the older individuals. 



Anterior teeth usually 3 in number, varying from 2 to 4. They are 

 long, slender, and diverging distally. The appearance of the anterior 

 teeth, together with the skeletal areas upon which they rest, as two 

 pronounced triangular spaces, offers an almost certain criterion for the 

 identification of this species with the unaided eye. 



■Posterior teeth 2 to 4, rarely 5 in number. I have never found a 

 specimen with more than 5, and but one with that number. Similar to 

 anterior teeth in form but usually longer. 



Seizing jaws (pi. 4, figs. 27, 28) 6 to 9 in number. Curvature about 

 75 per cent. Points with oval base, and imbedded from 25 to 30 per 

 cent of their height into shaft. Tip of point blunt. Shaft below point, 

 in most instances, provided with a short, massive crest which extends 

 proximally for a short distance on a line with the edge of the point, 

 and then makes an abrupt turn inward toward the shaft. Pulp-canal dis- 

 placed slightly toward the back of shaft. Pulp evenly distributed and 

 extending into the point from 55 to 66 per cent of its height. 



