^ET. n NEW LARVAL NEMATODES SCHWARTZ 3 



An examination of Doctor Cobb's specimen showed it to be an 

 immature Pon'ocaeciim coDsiderably smaller than Porr^ocaecum 

 encapsulatum, the mouth structures being, however, someAvhat more 

 developed than those in the latter species. The larval nematode 

 from the mole (Scalojms aqv.atictis) is quite distinct from the form 

 found in the shrew {Blurina brevicauda) and is described as a new 

 species, the name Porrocaecum americanufn being proposed for it. 



PORROCAECUM AMERICANUM, new species 



The worm in its preserved state has been removed from its cyst, 

 and is coiled in a loose spiral, having the shape of the figure 6 

 (fig. 3). Doctor Chapin states that the worm in its encysted con- 

 dition was tightly coiled, completely filling its capsule. The speci- 

 men is 7.9 mm. long and 225[i. wide in the middle of the body. The 

 cuticle is cross striated throughout the entire length of the specimen, 

 the striations in the middle of the body being approximately ISjx 

 apart, the distance between the striations diminishing as the two 

 extremities are approached. The mouth structures are more 

 developed than those of Porrovaecum enca-pmlatum^ the three 

 lips (fig. 2) appearing as distinct and well-defined structures, 

 the dorsal lip being larger than the two lateral lips. In 

 lateral view, cuticular prominences, such as those in Porrocaecum 

 e7icapsulatum^ are not distinguishable. The esophagus (fig. 4) con- 

 sists of two parts, namely, the esophagus proper and a ventriculus. 

 The former is about 690[j. long and the ventriculus which is oblong 

 in shape is 133(1. long by about 80[;. in mamimum width. The nerve 

 ring is located at a distance of ITSfx from the anterior extremity. 

 The intestinal caecum (fig. 4) is 440[jl long and lies alongside the 

 esophagus. The intestine whose diameter is more or less uniform, 

 measuring about 80[;, in the middle of the body, terminates at a dis- 

 tance of lOTpi. from the posterior extremity (fig. 1). The tip of the 

 tail (fig. 1) is apparently broken off as the posterior extremity of 

 the specimen has a truncate appearance that suggests an artifact. 

 No evidence of a genital opening or of gonads could be found in 

 this specimen. 



Hosts. — Scalojms aq vaticm. 



Location. — Under the skin. 



Locality. — Falls Church, Virginia. 



I'yj^e specimen. — United States National Museum, Helmintho- 

 logical Collections No. 26060. 



EARLIER REPORTS OF ENCYSTED NEMATODES IN INSECTIVORA 



The first record of the occurrence of encysted nematodes in Insec- 

 tivora was published by Goeze (1782), who found some spirally 

 coiled worms inclosed in cysts and lodged in the peritoneal cavity of 



