144 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



form obviously belongs to the genns Amphicaecwm, which Walton 

 erected in 1927 for some larval forms obtained by Leidy from the 

 weakfish {Gynoscion r eg alls). Walton presents no measurements 

 but gives a diagram of the digestive system of a 15 mm specimen. 

 In this it is clear that the intestinal cecum and esophageal appendix 

 are smaller relative to the esophagus than in my specimens, and the 

 two are therefore believed to be specifically distinct. 



RHAPHIDASCARIS ANCHOVIELLAE. new species 



Specific diagnosis. — Females 4 to 6 mm long, with maximum di- 

 ameter of IGOju, to 250/A. Head truncated, 60ju to 72ju, in diameter. 

 Esophagus, in specimens 5 to 6 mm long, about 600/* to YSO/i long 

 and 90^1. to 100/* broad, with a small bulblike posterior ventriculus 

 from which springs a posterior flattened appendix 310/x to 420/x long 

 and about 25/* in diameter dorsoventrally and about 60/* in diam- 

 eter from side to side. Ventriculus about 30/* to 50/* long and 90/* 

 broad. Vulva 1.2 to 1.5 mm from anterior end. Ovejector directed 

 posteriorly, dividing into two posteriorly directed uteri about 630/i 

 from vulva. Uteri loop forward, but not anterior to vulva, and 

 then pursue a wavy course backward, ending near anus. Anus 

 about 240/* to 300/* from posterior end. Tail bluntly conical, ter- 

 minating in a spine. 



Males about 4 to 5.8 mm long wdth diameter of about 105/* to 235/*. 

 Esophagus 410/1 to 500/* long and 65/* in diameter, with ventriculus 

 30/* long and 50/i broad, and posterior appendix 240/t to 280/i long. 

 Reproductive tube extends anteriorly to about 350/i behind end of 

 esophagus and pursues a wavy course posteriorly to cloaca, which 

 is 90/1 to 120/1 from posterior end. Tail abruptly conical at tip and 

 terminated by a spine. 



Specimens in anchovy immature with reproductive tubes present, 

 but without adult lips and without spicules in males. 



Host. — Anchoviella epsetus. 



Location. — Intestine. 



Locality. — Galveston Bay, Tex. 



Type specimen. — U.S.N.M. Helm. Coll. no. 39537; paratypes, no. 

 39538. 



Remarks. — These immature worms correspond in the structure of 

 the alimentary canal with members of the genus RhaphidascarfS. 

 Their specific identity is uncertain, since they are immature, but 

 until the adult stage can be obtained by infection experiments it 

 seems advisable to designate this species by a new name, even though 

 it may subsequently fall into synonymy. 



A few specimens of a larval form probably identical with this spe- 

 cies from the anchovy were found in Menidla menidia, and also in a 



