SPOROCHNUa 



SQUALID^. 



-i 



Mraight (y), bearing upon it the granular bodies arranged in a spiral 

 whose expression i* {. The granular bodies, or sporangia, consist of 

 two part* : first, the upper surface, which presents a number of small 

 globular bodies, e, called ovules, and are surrounded by a little pro- 

 jecting hood surmounted by a papilla ; and, second, the under surface, 

 which presents a number of little membranous sacs, which are filled 

 with grains resembling pollen, and hence hare been called anthers. 



SPOROCHNUS. [Aujjs.1 



SPORULES, or SPORES, the minute organs in Cryptogatnio or 

 Flowerlees Plants from which new plants are produced, answering to 

 the seeds in the Phanerogamic or Flowering Plants. Although these 

 organs perform the same office in the economy of the plant as seeds, 

 yet they differ essentially in the relation they bear to the new plant 

 Although in some instances they stand in the same relation to the 

 joung plant as seeds, yet they not uncommonly are found to be the 

 bomologues of buds. They generally differ from seeds in their origin, 

 structure, and germination. 



The situation of the sporules is exceedingly various. In the Fungi 

 and Alga they are frequently diffused throughout the substance of 

 the plant without any proper covering or receptacle. In the higher 

 forms, as the Mosse*, Ferns, Jungermannios, Ac., they are contained 

 in a special organ called the Sporangium. [REPRODUCTION IN PLANTS 

 AKD ASIMALS ; SPORAKGIUM.] 



SPRAT. [CLUPEIDA] 



SPREM3ELIA. [EPACRIDACEJB.] 



SPRING-BUCK. [AsTiLOPEJt] 



SPRINGa (WATEB.] 



SPRINGS, MINERAL. [WATER.] 



SPRUCE-FIR. [ABIES.] 



SPUR- WING. [RALUD.E.] 



SPURGE-LAUREL. [DAPHNE.] 



SQUA'I.ID.K, a family of Fishea of the section Chondropterygii. 

 In this family, which includes the various species of Sharks, the 

 branchiae are attached by their outer margin to the skin, and the 

 water taken in for respiration makes its escape through narrow outlets 

 corresponding in number to that of the interspaces between the 

 branchiae : the number of these openings is usually five. So far the 

 present fishes agree with the Ray or Skate family (R.uip.t:] ; but the 

 peculiar rhomboidal form of the body renders it easy to distinguish 

 the Rays, which moreover have a peculiar cartilage arising from the 

 nasal part of the skull, and extending towards and even meeting the 

 anterior part of the crest of the pectoral. This character is pointed 

 out by Miiller and Hcnle, who state that it is found in all the Ray 

 tribe, and also in Rkinolutut and J'rittii, whereas there is no trace of 

 it in any Shark. 



In the Sharks the body is elongated, and tapering gradually from 

 the head to the tail, or but little dilated in the middle. The muzzle 

 is rounded or pointed, depressed, and projects over the mouth ; the 

 nostrils are situated on the under side of the muzzle, in the form of 

 oblique openings, which vary somewhat in figure, according to the 

 species. The fins generally consist of two dorsals, two large pectorals, 

 two ventrals, an anal fin, and a caudal, the form of which is peculiar. 



The portion of the tail of the Shark which supports the tail-fin is 

 almost always bent upwards at an obtuse angle with the body ; the 

 fin iUelf may be divided into three parts a superior, an apical, and 

 an inferior portion; that which runs along the upper surface is usually 

 narrow ; that on the under surface is broader, but decreases in width 

 to it* point of junction with the apical portion, which is more or less 

 dilated at the extremity and obliquely truncated. Such is the most 

 common character of the tail and tail-fin in the present fishes, and 

 one which is not found in any recent fishes not belonging to the 

 Cbondropterygian group. 



The Male Sharks are smaller, and differ externally from the Females 

 in possessing two elongated appendages, one of which is attached to 

 the hinder edge of each of the ventral fins, the uses of which are not 

 known. Some species of sharks bring forth their young alive, whilst 

 others are inclosed in oblong simitransnarent horny cases, at each extre- 

 mity of which are two long tendrils. These cases are frequently 

 found on the sea-shore, and are called Sea-Purses, Mermaids' Purses, 

 4c. They are deposited, observes Mr. Yarrcll, by the parent shark- 

 near the shore in the winter months. The convoluted tendrils, 

 banging to sea-weed or other fixed bodies, prevent the cases being 

 washed away into deep water. Two elongated fissures, one at each 

 end, allow the admission of sea-water ; and the young fish ultimately 

 capes by an opening at the end, near which the head is situated. 

 For a short time the young shark continue* to be nourished by the 

 viulline fluid contained in the capsule attached to its body by the 

 connecting pedicle, till hnving acquired the power of taking food by 

 the mouth, the remains of the ovum are taken up within the abdomen, 

 as in birds and some other animals. 



" A curious peculiarity has been observed in the young both of the 

 Shark* and Skates during a very early stago of their existence. From 

 each of the branchial apertures branchial filaments project externally; 

 each filament contains a single minute reflected vessel, in which the 

 blood is thus submitted to the r.ction of the surrounding medium. 

 The appendages are only temporary, ami the blood of the fish is after- 

 wards aerated by the true gills. This very interesting discovery, 

 which, I believe, is of recent date, forcibly reminding us of the tem- 



poral external branchial in the young Batrachian Reptiles in the 

 tadpole state, has been observed by Mr. Richard Owen in the Blue 

 Shark (Carchariat glautiu) by Mr. John Davy, in the Torpedo ; and 

 by Dr. Allen Thompson, of Edinburgh, in the Thornback. Cuvier 

 had previously noticed it, and, in the Ucgne Animal,' has referred to 

 a figure, published by Schneider, of a very young shark in this 

 condition, for which, regarding it as the normal state of the fish, 

 that industrious pupil of Bloch had proposed the name of Squal.i 

 ciliaru." (Yarrell.) 



The teeth of the Sharks are arranged in several series, one within 

 the other, of which the outermost row is that in use ; the other rows 

 are decumbent, and serve to replace the foremost when injured. Their 

 form varies much in the different species, and even those of the upper 

 and lower jaw are often very dissimilar. Though very variable how- 

 ever, they most commonly exhibit modifications of a triangular form, 

 are sharply pointed, and have the lateral edges sharp and frequently 

 serrated. It is upon the modifications observable in the form of the 

 teeth, the form of the snout, mouth, and lips, and of the caudal fin ; 

 the existence or absence of the eyelid (membrana nictitans), spiracles, 

 and of the small depression on the root of the tail ; the situation of 

 the branchial openings, and of the dorsal fins, &c., that the various 

 divisions of the present family are formed. 



The Squalida and Raiida have long occupied the attention of Pro- 

 fessor Miiller and Dr. Heule, who have conjointly published an excellent 

 work on these groups, ' Systematische Beschreibung der Plagiostomen.' 

 The characters of the various genera into which they divide the Sharks 

 are here given. At the head of the Sharks these authors place the 

 Scyllia, a group in which the species have the teeth small and pointed, 

 and with one, two, or more lateral denticles; an anal and two dorsal 

 fins ; the first dorsal placed behind or opposite, but never before the 

 abdominal fins ; the spiracles are distinct in all, and tolerably large in 

 most of them ; the eyelid (membrana nictitans) is wanting. To this 

 section belong, as it would appear, all the oviparous sharks. 



Scyllium, Cuv. This genus is restricted to such species as have the 

 anal fin placed nearer to the head than the second dorsal fin. Eleven 

 species are known, of which three are found on the British coast : 

 the Small Spotted Dog-Fish (S. canicnla), the Large Spotted Dog-Fish 

 (S. catuiui), and the Black-Mouthed Dog-Fish (S, mdanoitomum). 

 (Yarrell.) 



Priitiuriu, Bonap., differs from ScyUium in having a long snout, 

 and also in possessing a series of larger scales, arranged like the teeth 

 of a saw on the upper edge of the tail. It contains but one species. 



Chiltact/llium. In this genus the anal fin is placed farther back 

 than the second dorsal, and the last branchial opening approximating 

 to the fourth. The under lip is broad and membranaceous, and 

 separated from the skin of the throat by a kind of furrow ; the upper 

 nasal valve bears a cirrhus. Four species are known. 



J/cmiscyllium, Miiller and Heule. Here the situation of the fins is 

 the same as in Chilotcyllium ; the nose and mouth as in ScyUium. 

 One species. 



OoMorAi'mis, Miiller and Heule. Remarkable for a great number 

 of small membranaceous lobules situated between the nostrils and 

 the first branchial opening. The mouth is nearly at the extremity of 

 the muzzle ; the two dorsal fins are placed towards the posterior end 

 of the animal, the first of them being situated above, and a little 

 behind the abdominal fins. This genus is founded on the SqtuUu* 

 lobatut of Bloch, the only known species. 



Qinglymtatoma, Miiller and Heule. It has small spiracles ; the two 

 last branchial openings approximating to each other ; the first dorsal 

 fin above the abdominal fins, and the second dorsal opposite the anal. 

 In adult specimens the inferior part of the fold bordering the corners 

 of the mouth is distinctly separated from the skin of the lower jaw 

 by a vertical furrow. The number of lateral denticles to the teeth is 

 four on each side. One species. 



Sttgoitoma, Miiller and Henle. In this genus the first dorsal fin 

 begins a little before the abdominal ones. The bronchial openings 

 are as in CitilotcyUium. A largo and thick wreath or rim conceals 

 the upper jaw, and the opening of the mouth, which is placed trans- 

 versely : the nasal valves are reduced to lateral edges of this wreath. 

 The teeth are in the form of trilid leaves. Type and only species of 

 the genus, Squaltu fatciatut, Bloch, Schn. 



The second division of Sharks contains species having, like the 

 Scyllia, an anal and two dorsal fins, and five branchial openings ; but 

 the first dorsal fin is always placed between the pectoral and abdominal 

 fin*. 



A large group is distinguished by tho possession of a membrana 

 nictatans, by the situation of the second dorsal fin, which is opposite 

 the anal one, and by the situation of the branchial openings, the last 

 or hut two of which are always placed above the base of the pectoral 

 fins. They aro divided as follows : 



A. Without Spiracles. 

 a. Teeth flat, sharp, the edges serrated or smooth. 



1. Carachariat, Cuv. Teeth flat, sharp, nnd serrated on each side, 

 either in the upper jaw only, or in both jaws. Spiracles are never 

 met with in the adult specimens, though the rudiments of these organs 

 may be observed in the foetus of a few species. Twenty npecies 

 of this genus are known, three of which are British : C. ylaucus, 



