ECHTUROID FAUNA OF NORTH PACIFIC — FISHER 487 



inflation. Characteristic is a flaplike nephrostome of variable but 

 conspicuous size (upward of 4 mm. long) having a lobed or laciniate 

 border and a crescentic slit near base on anterior or ventral side. It 

 is much larger than in inamoenits, which lacks the lobes. Both speci- 

 mens are males. 



Anal vesicles two, thin-walled, voluminous at base and terminally 

 slender. They are 40 to 60 mm. long and hence over half the length of 

 body. A characteristic feature is the presence of one or two broad 

 frenula at about two-thirds the length from base. These, and slender 

 frenula near the base, anchor the vesicles to body wall. Ciliated cups 

 are widely scattered on surface of vesicle. The cloaca is very small, 

 the length sufficient only to accommodate the base of the vesicles which 

 are attached close together on the ventral side. Mucosa of cloaca is 

 longitudinally plicated. A slight thickening of tissue at end of ciliated 

 groove, where the intestine joins the cloaca, may represent a vestigial 

 coecum, but it is very small, and not comparable to the normal coecum 

 of Thalassema. 



Alimentary canal excessively long, with numerous coils attached to 

 body by a multitude of rather strong frenula. In a specimen 80 

 mm. long, having the gut not overstuffed with pellets, the foregut is 

 30 mm., presiphonal intestine 200 mm., siphonal segment 160 mm., and 

 postsiphonal, provided with ciliated groove, 235 mm. ; total, 652 mm. 

 The foregut is not clearly subdivided. Back of the pharynx- esopha- 

 gus there is a region about 9 mm. long having the ring markings of the 

 gizzard, leaving an unusually short segment for the stomach ( C) . The 

 very long presiphonal intestine has no ciliated groove. The anterior 

 portion of it lies near the nerve cord and proceeds to posterior end of 

 body, where there is a sharp bend forward. 



The blood system is characterized by an indirect or capillary con- 

 nection between the dorsal and neurointestinal vessels, no ring vessel 

 being present. The neurointestinal vessel forms a small loop around 

 the interbasal muscle of setae ; in inamoenus the loop is not present. 



Type.—V.^.'^M. No. 21085. 



Type locality.— Albatross station 4525, Monterey Bay, Calif., 9.4 

 miles northeast of Point Pinos, 222 fathoms, soft gray mud, May 26, 

 1904, 2 specimens. A third mutilated specimen and five proboscises 

 were in container. 



ARHYNCHITE PUGETTENSIS, new species 



Plates 31, 32 



Diagnosis. — Differing from A. calif omicus in having a conspicuous 

 ring blood vessel at end of foregut and a well-developed ciliated groove 



822650 — 49 2 



