INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 551 



worm-like bodies. They are hermaphrodite, and have neither ten- 

 tacles, eyes, radula, or jaws. The foot is long and narrow, and can 

 be completely concealed by the mantle. The branchise, which are 

 placed at the posterior extremity of the animal, are retractile. Heart 

 with a pretty well developed vascular system. Generative organs 

 situated along the back, above the stomach and intestine. Nervous 

 system composed of an cesophageal ring with one cerebral and two 

 pedal (infra-cesophageal, TuUb.) ganglia. 



Family 1. Solenopodidce K. and D. 

 {NeomeniadcB Jhering.) 



Along the ventral surface a furrow, within which the long narrow 

 foot is concealed. Branchite filiform. 



Genus 1. Solenopus M. Sars, 1868. 

 Vermicidus Dalyell, 1853. Neomenia T. Tullberg, 1875. 



Body cylindrical, with filiform branchiae at its posterior truncated 

 extremity. Above the branchial cavity in the posterior margin of the 

 mantle a genital pore, and in the bottom of the branchial cavity an 

 anal orifice. Buccal mass, thick, muscular, capable of being com- 

 pletely covered by the mantle which is covered all over with diversely 

 formed calcareous spicules. Along the ventral surface a furrow in 

 which the foot is concealed. 



Six new species, in addition to S. nitidulus M. Sars, are described, 

 viz. : — S. affinis, S. DahjelUi, S. incrustatus, S. margaritaceiis, S. 

 borealis, and S. Sarsii. 



Organ of Bojanus in Anodon.* — Dealing with the view that the 

 blood of the Lamellibranchiata becomes intermixed with water in 

 the kidney (for such the " organ of Bojanus " is), Mr. Marcus Hartog 

 points out that this can hardly be so, and that the true function of 

 the water which enters its canal is that of flushing the renal ducts 

 filled with what is now known to be, on the whole, solid excreta 

 (Lacaze-Duthiers). The author points out that the foot is provided 

 with a number of orifices without any rigid elements adapting them 

 to resist compression, and with a supply of cilia which work inwards ; 

 the water which thus gains ingress must, on the contraction of the 

 foot, pass away partly by its pores, partly through the " vena cava," 

 and partly through the pericardium, whence it miTst escape through 

 the kidney, which, as is well known, has an orifice into the pericar- 

 dium ; it is further pointed out that the cilia of the renal canals work 

 towards the exterior, and that the external orifice is so arranged as to 

 prevent water passing in from without. 



MoUuscoida. 



Development of the Salpidse.f — The question whether these 

 interesting forms do or do not exhibit true alternation of generation is, 

 curiously enough, bound up with the history of the development of 

 their testes. According to one of the few naturalists who have 



* ' Journ. Anat. and Phys.' (Humphry), xiii. (1879) p. 400. 

 t ' Zeitbchr. wi.ss. Zool.,' xxx. (Suppl.) (1S7») p. 275. 



