GLOSSAKT. 309 



SIPHONOSTOMATA (Gr. siphon ; and stoma, mouth). The division of Gas- 



teropodous Molluscs, in which the aperture of the shell is not 'entire,' 



but possesses a notch or tube for the emission of the respiratory siphon. 



SIPHTJJTCLE (Lat. siphunculus, a little tube). The tube which connects 



together the various chambers of the shell of certain Cephalopoda (e.g. 



the Pearly Nautilus). 



SIPTJNCULOIDEA (Lat. siphunculus, a little siphon). A class of Anarthropoda 



(Annulosa). 



SOMATIC (Gr. soma, body). Connected with the body. 

 SOMATOCYST (Gr. soma ; and kustis, a cyst). A peculiar cavity in the 



ccenosarc of the Calycophoridce (Hydrozoa). 

 SOMITE (Gr. soma). A single segment in the body of an Articulate 



animal. 



SPERMARIUM. The organ in which spermatozoa are produced. 

 SPEBMATOPHORES (Gr. sperma, seed ; and ph<ro, I carry). The cylindrical 

 capsules of the Cephalopoda, which carry the spermatozoa ; sometimes 

 called the ' moving filaments of Needham.' 



SPERMATOZOA (Gr. sperma, seed; and zoon, animal). The microscopic fila- 

 ments which form the essential generative element of the male. 

 SPICULA (Lat. spiculum, a point). Pointed needle-shaped bodies. 

 SPINNERETS. The organs by means of which Spiders and Caterpillars spin 



threads. 

 SPIRACLES (Lat. spiro, I breathe). The breathing-pores, or apertures of the 



breathing-tubes (trachese) of Insects. 



SPLANCHNOSKELETON (Gr. splagchnon, viscera ; skeletos, dry). The hard 

 structures occasionally developed in connection with the internal organs 

 or viscera. 



SPONGE-PARTICLES. (See Sarcoids.) 

 SPONGIDA (Gr. spoggos, a sponge). The division of Protozoa, commonly 



known as Sponges. 

 SPORES (Gr. spora, seed). Germs, usually of plants; in a restricted 



sense, the reproductive ' gemmules ' of certain Sponges. 

 SPOROSACS (Gr. spora, seed; and sakkos, a bag). The simple generative 

 buds of certain Hydrozoa, in which the medusoid structure is not deve- 

 loped. 



STATOBLASTS (Gr. statos, stationary ; blastos, bud). Certain reproductive 

 buds developed in the interior of Polyzoa, but not liberated until the 

 death of the parent organism. 



STEGANOPHTHALMATA (Gr. steganos, covered ; and ophfhalmos, the eye). 

 Applied by Edward Forbes to certain Medusas, in which the sense-organs 

 (' marginal bodies') are protected by a sort of hood. The Steganophthal- 

 mata are now separated from the true Medusidce, and placed in a sepa- 

 rate division under the name Liicernarida. 

 STELLERIDA (Lat. stella, star). Sometimes employed to designate the order 



of the Star-fishes. 

 STELLIFORAI. Star-shaped. 

 STEMMATA (Gr. stemma, garland). The simple eyes, or 'ocelli,' of certain 



animals, such as Insects, Spiders, and Crustacea. 

 STERNUM (Gr. sternon). The breast-bone. 

 STIGMATA. The breathing-pores in Insects and AracJinida. 

 STOLON (Gr. stolos, a sending forth). Offshoots. The connecting processes 

 of sarcode, in Foraminifera ; the connecting tube in the social Ascidians ; 

 the processes sent out by the ccenosarc of certain Actinozoa. 

 STOMAPODA (Gr. stoma, mouth : and poiis, foot). An order of Crustacea. 

 STOMATODE (Gr. stoma). Possessing a mouth. The Infusoria are thus often 

 called the Stomatode Protozoa. 



