67 



wing large papillary prominences which 

 appear to have a function like that of the 

 intestinal viliosities of the vertebrates. The 

 posterior extremity of the males also pre- 

 sents an interesting disposition since it is 

 depressed and slightly excavated, appearing 

 to have the function of a suction apparatus- 

 besides having the cuticle corrugated and 

 presenting obliquely disposed muscles as 

 are noted in the Ktithlanidat. 



Up to the preseni this fa nily has only 

 one genus with only one spt;c es. 



Genus Cruzia, TRAVASSOS, 1917. 



Characters of the family : 



Only species: C. tciUaculata (RUD., IS 19) 

 TRAV. 1917. 



Cruïia tentaculata (RUDOLPHI, 1819) 



(PI. Fig. 1—12.) 



Syn: Ascaris tentaculata RUD. 1819 p. 

 168. 

 Ascaris tentocnlata DU J. 1845 p. 

 168. 



DIESING, 185! p. 



« LF.IDY, 1855 p. 



« DIESING, 1860 p. 



147. 



51. 



655. 

 Oxysoma <- SCHNEIDER, 1866, 

 p. 155 (pi. Vll, fig. 13, p. XV, 

 fig. 1). 

 Craz/a tentaculata. TRAV. 1917. Br. Med. 



Ann. 29, n. 12. 

 Length: S 9 8 to 16 mm., the males 

 being slightly smaller. 



Breadth: cT 9 0,52 to 0,67 mm. 

 A helminth of white color, slightly mo- 

 tile, attenuated at the extremities, the grea- 

 test diameter being preequatorial; cuticle 

 smooth, thick; mouth protected by three 

 subtriangular lips; buccal capsule or vesti- 

 bule narrow, trilateral, measuring 0,106 to 

 0,156 mm. in length; oesophagus cylindrical, 

 with spherical bulb, measuring without the 

 bulb 1 to 1,9 mm. in length 0,10 to 0,12 mm. 

 in width; the bulb measures 0,31 to 0,48 mm. 

 in diameter; intestine with anterior diverti- 

 culum about 0,9 to 1,2 mm. mm, in length ; 



nerve ring 0,46 to 0,60 mm. from the an 

 terior extremity; excretory pore 1 to 1,4 mm. 

 from the extremity. 



Female with the vulva in the mid portion 

 of the body: ovijector claviform; ova 0,120 

 by 0,056 to 0,063 mm.; anus 0,8 to 1 mm. 

 from the extremity; male with 9 pairs of 

 papillae, 3 postanal approximate, 3 adanal 

 and approximate, and 3 preanal, separated ; 

 spicules equal, 0,8 to 1,1 mm. in length; 

 gubernaculum flat, 0,19 to 0,24 mm. in 

 length; anus 0,21 to 0,29 mm. 



Habitat: Large intestine of Didelphis (D.) 

 au rita, WIED; Didelphis (D.) virginiana 

 KERR (1); Didelphis (Philander) philander 

 L.; Didelphis (Philander) lanígera DESM. ; 

 Didelphis (Metachirus) opossum SEBA; Di- 

 delphis (Peramys) domestica WAG. ; Didelphis 

 (Mormosa) marina L, ; Didelphis (Metachirus) 

 nudicaudatus GEOFF. 



Body white, attenuated at the extremi- 

 ties, especially at the caudal extremity of 

 the females; greatest diameter just below 

 ttie termination of the esophagus. 



Cm/zV/í".— Cuticle thick, smooth, without 

 transverse striation or lines and longitudina- 

 wings. The comparatively great thickness 

 and impermeability of the cuticle make the 

 embedding in paraffin for histological sections 

 especially difficult. 



Body ifa/Zs.— The walls of the body are 

 formed by muscular fields which are made 

 up of 3 fibers of cells joined obliquely 

 (fig. 2), as is observed in the majority of 

 nematodes, but one of the fibers is incom- 

 plete as shown by the figure. In transverse 

 sections these cells appear sub-quadrangular, 

 having three nearly plane surfaces with the 

 periphery strongly differentiated into mus- 

 cular fibrillae, and a curved one with diffe- 

 rentiation forming trabeculae which are fixed 

 on the digestive tube or on other cells, that 

 is, the external and lateral faces are stron- 

 gly differentiated into contractile fibrillael 

 The longitudinal fields are distinct and wide. 



(1) It is not impossible that the North American 

 speciess different from the South American. 



