Alloiodoris.] GASTROPODA. 509 



as long and wide as the body ; in front it is grooved, and the tliin 

 upper lamina is divided by a median notch. 



Length. 33 mm. : breadth, 23 mm. (type). Length. 50 mm. ; 

 breadth, 33mm. : height. 16mm. (Cook Strait specimen). 



On the labial cuticle is an armature, which, though large enough to 

 be seen by the naked eye, is curiously shadowy, heing not a compact 

 plate, but a loose collection of rods, almost transparent in some places, 

 thicker in others. But, though so unsubstantial, it is fairly definite 

 in outline, consisting of 2 plates prolonged into tail-like appendages. 

 The elements are longish rods, often wavy and transversely striated, 

 sometimes, but not consistently, hooked at the tip. 



The nitlula consists of 26 rows, containing 40-45 teeth on either 

 side of the rhachis. There is no rhachidian tooth, but the first laterals 

 project into the rhachis and almost meet. They have a few denticles 

 on the outside, and on the inside a jagged prominence bearing 1 to 3 

 denticles. The second tooth has a small prominence near the base 

 on the inner side and denticles on the outer side. The succeeding 

 teeth increase rapidly in size until they assume the normal form 

 this is short, stout, and strongly hamate ; on the outer side of each 

 tooth is a ridge terminating above in a rather blunt point ; in the 

 first 10-15 teeth this ridge bears several (generally about 6) very 

 irregular denticles ; after the fifteenth tooth these denticles disappear, 

 and only the point remains as a single denticle. It is found in all the 

 teeth except the last three, which are thin and irregular in shape, 

 but not serrulate. 



The hermaphrodite gland does not form a layer over the liver as 

 usual in Dorids, but is a separate yellowish mass, about 15 mm. long 

 and 10 mm. broad. (Eliot.) 



Sir C.. Eliot gives a full account of the internal anatomy in his paper 

 in P. Mai. S., vii. 



Type in the British Museum. 



Hab. Takapuna ; Cook Strait (H. S.). 



Remarks. A. marmorata, Bergh. is perhaps a distinct species, 

 and Basedow and Hedley's A. marmorata differs in coloration and in 

 the radula from A. marmorata, Bergh, and A. lanuginata, Abrah. 

 (Eliot.) 



Genus 4. GARGAMELLA, Bergh, 1894. 



Gargametta, Bergh, Bull. Mus. Cornp. Zool. Harvard, xxv, 1894, 175. Type : 

 G. immaculata, Bergh. 



Body somewhat depressed, with nearly the whole of the notum 

 sericeous in appearance ; tentacles digitiform ; branchial plumes tri- 

 pinnate ; foot bilabiate anteriorly ; upper lip with a median fissure. 



There is no labial armature. Radula without a central tooth, the 

 lateral teeth multidentate, the denticles hooked. Prostata large ; 

 male organ armed with hard orbicular discs with a central hook. 

 Vestibular glands are present. 



The oenus is recorded from the south-west Atlantic. 



