306 ICHTHYOMENIA-PARAMENIA. 



animal is the large and strongly two-lipped cloaca, which looks like- 

 the mouth of a reptile or fish. 



Off the mouth of the Tech, in 80 meters depth, among Bryozoa 

 and Hydroids. 



Ismenia ichthyodes PRUVOT, Arch. Zool. Exper. (2), ix, p. 719,. 

 784, pi. 25, f. 3; pi. 31, f. 79, 80 (1891). SIMROTH in Bronn, p. 

 232, pi. 9, f.7-11. 



Genus PARAMENIA Pruvot, 1890. 



Paramenia PRUVOT, Arch. Zool. Exper. (2), ix, p. 786. SIM- 

 ROTH in Bronn, p. 232. 



Body short, cylindrical, obliquely truncated behind. Cloaca ter- 

 minal. Spicules partly needle-shaped, partly fishhook-shaped 

 (PI. 47, figs. 87). Foot and foot-groove present, curving into the 

 cloaca. Radula with two longitudinal rows of teeth. Length 5 to 

 6 times the breadth. 



Two subgenera are recognized by Simroth, Paramenia and Par- 

 arrhopalia. 



Subgenus PARAMENIA (restricted). 



Cuticle thin, without sense-tubercles. Cloaca with a circle of 

 gills. No excitation-bodies. Length six times the breadth. 



P. IMPEXA Pruvot. PI. 47, figs. 83-87, 90. 



Body cream-white, cylindrical, 12 mill, long, 2 mill, wide, trans- 

 versely truncated, with 12-20 branchiae around the cloaca; supra- 

 buccal tubercle with two concentric coronse of lanceolate spicules. 

 Radula biserial. 



P. impexa is a stout form, incapable of coiling itself, with cream- 

 white, regularly cylindrical body, not keeled dorsally, rounded at 

 the head end but truncated 1 transversely by the cloaca (fig. 86). The 

 pedal groove is well developed, as well as the foot, and is continued; 

 to the cloaca as a ventral sinus. The spicules of the general sur- 

 face (fig. 87) are like those of P. pruvoti, but project a little less 

 from the integument. The two sensory knobs of head and tail are 

 very distinct, especially the latter (fig. 83), which is nearly cylin- 

 drical, very elevated, and bears, besides the usual corona of small 

 lanceolate spicules a complete covering of little acicular spicules, 

 very much crowded. The sensory knob of the head is distinguished 



