422 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



then turning posteriorly, sometimes entering ecsoma, sometimes not. 

 Testes subspherical, diagonal, close together, a short distance posterior to 

 acetabulum. Seminal vesicle a thick-walled, elongate or ovoid sac lying 

 close to and overlapping anterior testis ; an indistinct tripartite appearance 

 (fig. 106), sometimes evident within the vesicle [a condition similar to 

 that described by Woolcock (1935, p. 321) for Erilepturus tiegsi]. Pars 

 prostatica sinuous, usually forming a posterior loop and always overlap- 

 ping anterior end of vesicle, entirely postacetabular, not reaching appre- 

 ciably anterior to seminal vesicle ; prostatic cells present but not profusely 

 developed. Pars prostatica and a short narrow portion of uterus uniting 

 posterior to acetabulum to form a very long tubular ductus hermaphro- 

 diticus or genital sinus enclosed in a sinus sac. Sinus tube almost or quite 

 Ys body length, divided into 4 regions as follows: a narrow, almost 

 straight region slightly wider at its base, extending past acetabulum, sinus 

 sometimes with somewhat convoluted inner wall in anterior part of this 

 region, but tube is uncoiled. Just anterior to acetabulum occurs a thin- 

 walled, usually expanded region of the sac within which the muscular 

 sinus tube often becomes greatly coiled (fig. 107). This region is more 

 or less separated by a constriction at its posterior end and sometimes ap- 

 pears to be partially divided near its middle. The penislike sinus tube is 

 very evidently flexible and capable of protrusion; its tip end can usually 

 be seen in this saclike portion of the sac ; in a few specimens it is extended 

 into the next anterior and more muscular region. This muscular region 

 of the sac is long and straight, extending almost to the genital pore. It 

 measures 0.127 to 0.170 in length. The fourth region is a short, thin- 

 walled, tubular genital atrium leading to the genital pore. 



Ovary ovoid, transversely extended, not far posterior to testes, about 

 in middle of hindbody. Vitelline lobes fairly thick and of medium length, 

 thickened at tips with some slight indication of branching (fig. 105). 

 Seminal receptacle very small, embedded in Mehlis' gland. Laurer's canal 

 lacking. Uterus may or may not send a loop into ecsoma. Eggs thin 

 shelled, elongate, 14 to 17 by 6 to 8 /*. Eggs were seen within the ductus 

 hermaphroditicus and even in the sinus sac outside the ductus. Excretory 

 vesicle forking at base of seminal vesicle ; branches uniting dorsal to phar- 

 ynx. 



GENERIC DIAGNOSIS OF ELYTROPHALLUS 



Smooth-bodied, tailed Hemiuridae. Subfamily Dinurinae. Acetabu- 

 lum large, in anterior half of body. Genital pore ventral to oral sucker. 



