52 WEBB : BRITISH SPECIES OF TESTACELLA. 



Greyish brown form.— One specimen was of a very dark hue, with 

 dorsal furrows of a still darker colour : the foot-sole was of a creamy white, 

 and edged with a narrow line which was to all intents and purposes black, while 

 down the centre from head to tail, ran a narrow stripe of brilliant orange- 

 colour (apparently due to mucus as it could be removed.) Altogether the 

 animal presented a very Striking appearance. Only one dark specimen was 

 received from Brandon, and a few somewhat lighter in colour from another 

 locality. The shape of the body recalls somewhat that of the next form. 



Yellowish form. — This variadon resembles T. scutulum, in that yellow is 

 the predominant colour (in some cases even of its foot-sole), and in its more 

 cylindrical shape, but its shell, dorsal furrows, and internal anatomy are 

 typical of T. haliutuka. 



Testacella maugei. 



Tlie bronze variation of Morelet has not been seen by 

 the writer, unless the first form mentioned below be the one : — 



Tawny form. — The dark brown markings are fairly wide apart, but 

 give a brown appearance at first sight ; the ground colour being j-ellowish. 



Brown form. — The ground colour is nearly obscured by the numerous 

 markings. 



Yellow form. — The markings are restricted, and the general appearance 

 is yellow inclined to orange. 



Gassies and Fischer '■'■' mention albino, greyish black, greyish 

 brown, greyish red (type of Ferussac) and reddish brown 

 " varieties," which are not quoted in the Check List, probably 

 owing to the descriptions being so meagre. In some specimens 

 of the first form of T. maugei the dorsal furrows and lateral 

 grooves are so strongly pigmented that the likeness to a leaf is 

 very marked ; this leaf-like appearance was also noted under the 

 last species. The writer has often noticed also a strong likeness 

 between contracted specimens of 7". scntnlum (and in some cases 

 of T. halioiidca), and half a broken pebble, the arched upper 

 side of the slug corresponding with the original surface of the 

 pebble, and the slightly convex underside, with the fractured 

 surface of the flint, which is often higher in tlie centre. Corre- 

 spondents point out the difficulty of finding Testaccllae, as they 

 " favour stones" so much. 



Reproductive System. 



As the differences in the genital organs have been the chief 

 features relied upon for separating T. haliotidca and T. sctitulum, 

 it is as well perhaps to begin with the reproductive system of 

 our British species. 



The previous work of comparing these two species 

 is as follows : — ■ 



* Monogiaphie du Genre Testacelle, Actcs Linn. Soc. Bordeaux xxi. (1858), p. 230 



