144 GLOSSARY. 



tissue of Protozoa and Infusoria, which is as it were on its way to become 



true flesh. 



(o-avpa, a lizard ; oif is, appearance), a name applied to the classes 



Ates and Eeptilia collectively. 



(aavpa, ovpd, tail), an order of birds represented only by the extinct 



genus Arcliseopteryx, distinguished by having a long tail like a lizard's. 

 SCAPULA (form of spatula, dim. of spatla, airdOri, a broad, flat blade), the shoulder- 

 blade, called the " side-bone' 5 in birtls. 

 SCLEROTICA (tTK\iip6s, hard, sc. tunica), the capsule of the retina, the eye-ball, 



fibrous in Man, but partially ossified in many of the lower Vertebrata. 

 SCOLECIDA, a group of Annuloida or Vermes comprehending the Entozoa of Cuvier> 



and also the free Turlellaria. 

 SCOLEX (ffK&\ri, a worm), the larva in Scolecida, produced from an egg, which may 



by gemmation give rise to infertile deutoscolices, or to ovigerous proglottides. 

 SCUTUM (a shield), applied to the bony dermal plates in the skin of crocodiles* 



&c. : also the large dorsal scales of some Annelida. 

 SETIGEROUS (sete, bristles; gero, carry), especially applied to the locomotive 



Annelida. 

 SIKENIA (tieifrfiv, a siren, a mermaid), an order of Mammals, the Herbivorous 



Cetacea of Cuvier, including the genera Halicore (dugong), Manatus 



(lamantin), and the recently extinct Shytina ; the name is given because the 



dugong, from its pectoral mammso, was named Halicore, the sea-maiden. 

 SOMITE (<ra)/ia, body), a segment of the body of Annulosa, with its upper and 



lower pair of appendages. 

 SPERMATOZOA (trirep/io, seed ; Qfov, animal), animalcula seminis, minute organisms 



of characteristic shape, and endowed with spontaneous motion, found in the 



sperm-cells of a'l animals. 



SPIGTLUM (dun. of spica, a thorn), any hard, pointed animal structure. 

 SPIRACLE (spiro, to breathe), the lateral openings into the tracheal tubes of 



insects, &c. 



SPONGIDA (<nroyyid or ffiroyyos, a sponge Arist. H. A. ix., xiv. 3), a class of Protozoa. 

 SQUAMOSAL (squama, a scale), a membrane bune, wedged in between the auditory 



capsule and the ali-sphenoid : io Man it overlaps the parietal by a scale-like 



suture. 

 STAPES (a stirrup), so called from its shape in Man ; the auditory ossicle 



which is joined to the Fenestra ovalis, and corresponds with the Columella 



in Sauropsida. 

 STEGANOPHTHALMOUS (ffT-ryavos, covered ; 6$6a\fj.6s, eye), the acraspedote Medusae, 



an order of Hydrozoa. 

 STEMMATA (ore'^/ia, a garland), the simple eyes of Insects, often arranged in the 



form of a circle on the top of the head. 

 STERNUM (the cheat), applied to the azygos bone formed by the meeting of the 



visceral arches in front in most of the higher Vertebrata : also to the inferior 



pieces of the exoskeleton of Arthropoda. 



STIGMATA (crfy/io, a mark), a synonym of spiracula in Insects. 

 STOMAPODA (more properly Stomatopoda, fr. <rr^a, a mouth; irovs, foot), an 



order of Crustacea in which the organs of prehension retain more of the 



character of feet than in Decapods. 

 STREPSIPTERA (ffrptyis, a twist ; irrepov, wing), a group of Insects with the 



anterior pair of wings twisted. 

 STROBILA, or Strobilus (tn-pofiiXos, a fir-cone), a chain of zooids formed by a scotex 



