174 Records of the hidian Museum. [Vol. X , 



The anus (A — T=-2 mm.) is broad transversely and has a 

 prominent anterior lip. 



The oesophagus (fig, 35) has the form usual in the genus. 

 Circumoesophageal nerve ring not seen. A large unicellular gland 

 lies on one side of the oesophagus. 



Female gonads. The vagina runs forward from the vulva for 

 a distance of -55 mm. and is furnished with thick walls. The 

 uteri (two, anterior and posterior) are distended with eggs which 

 possess thin shells. The usual coiled ovarian tubes are visible in 

 front of and behind the uteri. 



Discussion of the systematic position. Comparison with : — 



1. D. fovcolata, R. {vide Dujardin (3) p. 270, Schneider 

 (19) p. y4) = D. esuriens, Duj, 



D. callichroi is a much more stout animal ^- = ' contrasted 



i.lv. 17 



with in D. joveolata. 



In figures 39 and 40, representations are given of the head 

 and oesophageal region of D. foveolata, R., horn. Pleuronectes platessa 

 (collected at Plymouth) for comparison with figs. 36 and 35, 

 respectively. Some measurements from D. joveolata are also in- 

 cluded in table IV (see page 187). The difference in the relation 



Oes. Br, . , j 



-Q — J- IS very marked. 



2. D. abbreviata R. (Dujardin, p. 269), in Perca cirrosa. 

 The description of this species is insufficient for recognition. 



3. D. globosa, Duj. (Dujardin, p, 269) from 5<?/mo/«no — isa 



larger animal than D. callichroi ? =16 mm., is thinner ~-^jr^=-- 



i.i/. 55 



°^^t°' — ■•■=— (- in D. callichroi). The head bears a tubercle on 

 its dorsal aspect which is absent in D. callichroi. 



4. D. hians, Duj. in Muraena conger. A larger animal than 

 D. callichroi, length 20*7 mm. contrasted with 6 7"S ^.^-^ — con- 



' ^ T.L. 39 



trasted with — . 

 17 



5. D. sphaeroccphala, Rud. fr. Acipenser microcephalus, a 

 larger animal, ? length 15-6 mm.: and thinner ^^^•=^ not — 

 Postanal ^ i ^^^ i ^ q^^ smaller — -052 X -027 contrasted with 



•085 X -055. 



6. D. squall, Duj., a larger animal, 9 length i8'5 mm., and 



, 1 . I / , . I \ Post Anal L i , 4. 1. i \ Hd. V. 



thmner — (contrast — ). t^tj = .^ (contrast - ). ., ^^ 



37 17 T.L. 56 ^ 39 ' v.T. 



I 



7. D. rotundata, Mol. (Molin (16) from Cantharus vulgaris, 

 Padua, description of 9 insufficient for recognition. 



