ASCARIS UECIPIENS. 



Ill 



Krabbe was not able to definitely determine whether or not this form was identical 

 with A. maritima, but Leuckart, who examined A. decipiens at Krabbe's request, 

 stated that it was specifically distinct from A. maritima. The two forms belong to the 

 same group, but there seems to be no evidence in support 

 of the view that A. maritima of man occurs in seals. 



Cobb (1888, pp. 59-64) described as a new species 

 A. ftwZ&osa, . some nematodes taken by Kiikenthal from 

 the stomach of Phoca iarhata (=Erignathus barbatus); 

 although certain important details of structure are omitted 

 in Cobb's article, there can be scarcely any doubt regard- 

 ing the specific identity of his form with A. decipiens, as is 

 shown by the following abstract of Cobb's work : 



The male (figs. 3, 4) measures 50 to 70'"™ long, with 

 cylindrical body attenuated anteriorly ; the head is about 

 0.33™™ broad, while the breadth of the body is one- twenty- '''' ' 



fifth to one-twenty-sixth of its length. The transverse striae can be seen only with 

 the aid of the microscope. The tail is curved and possesses papillae (fig. 4) which 

 can be distinguished with the hand lens. Cobb's figure shows 7 pairs of 

 postanal papillae; 1, 2, and 3 nearer the tip, 4, 5+6, and 7 nearer the 

 cloaca; praeanal papillae about 60 in number on each side, extending for- 

 ward in two irregular rows; in the figure the first five praeanal papillae 

 are smaller than those which follow; the spicules 

 measure 2 to 2.5'"'" long, are nearly similar, but the 

 left spicule (2.5'"™) is slightly longer than the right 

 (2.3 ™™). The female measures 50 to SO"™, the vulva 

 is situated somewhat more than one-third the length 

 of the body from the anterior extremity. The 3.3™™ 

 long oesophagus is composed of three portions: an 

 anterior portion 2*"™ long by 0.5™™ in diameter (broad- 

 est portion); a second bulb-like portion 0.33™™, and 

 rl terminal cylindrical portion 1'"™ long by 0.33™™ broad. 

 I The intestine possesses a proximal caecum. The ex- 

 cretory organ opens- between the ventrolateral lips. 

 Fig. 5. Qijjg vagina measures 2 to 3™™ long ; the uterus, includ- 

 ing the horns, 15 to 16™™; eggs develop to the morula stage in 

 the uterus. The cervical papillae are situated 0.5™™ back of the 

 mouth. From the fact that the excretory organ opens between 

 the ventral lips, intermediate lii)s must be absent. 



In his second paper Cobb (1889, p. 150) gives a short abstract 

 of his first article. 



Jagerskiold (1894, pp. 452, 467-474) determined as identical 

 with A. decipiens parasites preserved in the Zoological Institute 

 of the Upsala University and taken from the mouth and pharynx 

 of Halichoerus grypus Nilsson. From his anatomical discussion the following data 

 are abstracted. 



The oesophagus is divided into two portions: The anterior portion agrees 

 essentially with the corresponding portion of the oesophagus in "A. simplex^' as 



Fig. 6. 



