GENUS ALEPAS. 157 



maxillae notched, with the lower part irregular, projecting ; 

 caudal appendages multi-articulate. 



Attached to various living objects, fixed or floating. 



Capitulnm either entirely destitute of valves, or with 

 transparent horny scuta, not containing any calcareous 

 matter, and almost hidden in membrane. These scuta 

 are formed of a lower and a lateral lobe, placed at above 

 right angles to each other ; they are added to by successive 

 layers, and closely resemble in shape the scuta of the 

 Conchoderma aurita. The orifice in A. tubulosa projects 

 so much as to be almost tubular. In A. parasita and 

 A. minuta it does not project, and is either moderately 

 large, or very small in proportion to the length of the 

 capitulum ; from contraction it is much wrinkled. The 

 membrane forming the capitulum is smooth and very 

 transparent ; it contains very few tubuli, except under 

 certain irregular projections in A. cornuta. 



The Peduncle is rather short and narrow; it blends 

 into the capitulum, and is not, in some of the species, 

 separated from it by any distinct line; the surface of 

 attachment is rather wide. Within the peduncle we have 

 the three usual layers of striae-less muscles ; namely, the 

 innermost and longitudinal, which run lower down than 

 the others ; the middle and transverse; and, lastly, the ex- 

 terior, oblique muscles, which cross each other (becoming 

 transparent) on the rostral central line. These several 

 muscles run up from the peduncle and surround the 

 capitulum ; from the transparency of the membranes 

 they can be seen from the outside : they are particu- 

 larly conspicuous round the orifice, which they probably 

 serve to close. There is, in all cases, the usual adduc- 

 tor scutorum muscle (with transverse striae), which is 

 attached under the horny scuta, where such exist. The 

 fact of the striae-less muscles of the peduncle surrounding 

 the whole capitulum, has been observed only in one other 

 genus, namely Anelasma. In consequence of this struc- 



