SELACHINEMA 



A NEW NEMATODE GENUS WITH REMARKABLE 

 MANDIBLES. 



BY N. A. COBB 

 CONTRIBUTIONS TO A SCIENCE OF NEMATOLOGY, IV 



SELACHINEMA, new genus. 



Body slender; cuticle finely transversely striated; head armed with 

 powerful non-retractile dentate chitinous mandibles; amphids spiral; 

 tail armed with caudal glands and spinneret; oesophagus plain; renette 

 present; minute pores on the lateral lines. 



3.7 



9.0 

 8.1 



49Y 



89. 

 T.2 



Selachinema ferox, n. g., n. sp. 3.1 3.1 3.1 3.4 2.2 " The rather thin 



layers of the transparent, practically naked cuticle are traversed by exceedingly 



fine transverse striae resolvable 

 only with the aid of the highest 

 powers under favorable condi- 

 tions. Only a very few minute 

 hairs, hardly more than twice 

 as long as the cuticle is thick are 

 to be found on the body. The 

 cylindroid neck ends in a head 

 which diminishes in size very 

 slightly just beyond the am- 

 ; phids, and bears three (?) large, 

 solid, slightly inwardly arcuate, 

 projecting, powerful chitinous 

 jaws armed on the inner surface 

 with four longitudinal rows of 

 somewhat backward pointing 

 conical teeth, each row consist- 

 ing of four or five teeth. Each 

 f of the two submedian jaws is 

 composed of two parts of une- 

 qual size, that toward the dor- 

 sal side being the shorter, and 

 armed with two rows of teeth 



Fig. 1. Selachinema ferox, n.g., n.sp. a, the two power- . 

 ful submedian chitinous jaws, each armed with tour rows of OI about equal Size, Whllje one 

 retrorse teeth ; b, rudiment or remnant ot ventral jaw; c, lateral f ., . rr . wa nn tv, p othpr 

 setae (restoration) ; rf. submedian setae (restoration)-behind ' tn e two TOWS on tne Otner 

 may be seen two ot the tour small subceohalic setae; e, spiral na lf o f the mandible is COm- 

 amphids; /, base ot the pharynx. The head is a correct cam- 

 era lucida drawing. The body and tail have been drawn in posed of exceedingly minute 



perspective dotations. Between the two 



113 



