90 Snail-Leeches. 



an exception to the rule, and to resemble Piscicola in this par- 

 ticular as in others.* One point, however, in which the last 

 named worm differs from every species of Glossiphon, consists 

 in its mode of reproduction. The Piscicola, after depositing 

 her oval cocoons, leaves them, and the young never attach 

 themselves to the parent. 



G. Hyalina. — The most transparent of the family, and 

 widely distributed. Body when at rest oval and much dilated ; 

 colour of a transparent amber • back sprinkled with numerous 

 granular orange spots ; eyes, three pair, arranged as in G. 

 complanata. Anterior extremity pointed ; posterior abruptly 

 obtuse ; gastric casca six pairs, anterior smallest, and divided 

 upwards, the rest gradually increasing* to the last pair, which 

 immediately bends itself towards the posterior extremity. 

 It carries its ova (June and July) within the abdominal pouch, 

 like G. hioculata. This species is very inactive, and rolls itself 

 up when handled. After feeding the stomachal cseca become 

 of a bright vermilion, which, seen through the transparent 

 body of the leech, gives it a beautiful appearance. Miiller did 

 not exaggerate when he applied to this Glossiphon the title of 

 " Vermiculus splendidissimus."^ The specific name of Hyalina, 

 will enable the student to identify this Glossiphon at a glance. 



G. verrucata. — I know nothing of this species. It is said 

 to differ from G. comjjlanata in having seven pair of gastric 

 caeca, instead of six, and in having a body softer than that 

 species. 



G. eachana. — Found only in L. Neagh, Belfast, and de- 

 scribed by Mr. W. Thompson in the An. and Mag. of Nat. 

 Hist., vol. xviii. (1846). His description is as follows: — 

 "Body oval, anterior portion not dilated into a distinctly 

 formed head, back smooth, margin slightly crenulate, eyes 

 eight ; stomachal lobes subpinnate, prevailing hue hyaline. The 

 size commonly extends to nine lines. " Mr. W. Thompson says 

 of this species, " The glassy transparency rendered the vessels 

 of the digestive system, which were of a fine dark red colour, 

 very conspicuous, and owing to the jagged outline of the series 

 of lateral lobes, etc., the creature was so extremely beautiful 

 that it might be compared to an arborescent agate." Mr. 

 Thompson's figure somewhat resembles G. tessellata, bat it 

 appears to be a distinct species. 



Several other kinds of Glossiphonidce have been named as 

 claiming distinct specific recognition • but the descriptions are 

 in some cases very vague, and in others they clearly point to 



* Piscicola is often said to be incapable of swimming ; this is a mistake, it 

 swims readily. M. Moquin Tandon says, " Ces Hirudinees ne nagent point." 

 (Monograpli, p. 293.) 



f Verm. Terr est et Fhtiiat, ii. p. 50. 



