1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 543 



as far back as the most posterior ])()rtion of the carapace. The carims 

 is without spines. The maims has the usual tliree movable spines, aud 

 the marginal pectinations form a slightly undulating line. The dac- 

 tylns is rather slender and its outer edge is a siini)le curve except for a 

 scarcely perceptible tubercle near its base. It is armed with six teeth 

 that gradually increase in length from the base outward. The appen- 

 dages of the walking legs are linear. 



Size. — Length of body, 7.7 cm. 



Locality. — The single female specimen in the collection was taken by 

 the Albatross in 1885 in the Gulf of Mexico off Charlotte Harbor, N. 

 Lat. 2()0 18' 30", W. Long. 83^ 8' 45'' at a depth of 27 lathoms (^o. 

 9835, [J.S.X.M.). 



THE LARV^. 



The ontogeny of tlie Stomatopoda includes a remarkable metamor- 

 phosis, and the animals while in the larval stage bear so little resem- 

 blance to their adult fornj that it was but natural that the earlier 

 zoologists should su})])ose them to be adults of another family and 

 should give to them generic and specific names. We are indebted to 

 the researches of Clans (1871), Faxon (1882), and Brooks (1879, 1886, 

 and 1892) for our knowledge of the true relationslii]) of these forms. 

 While they are now only entitled to bear the names of adult species of 

 which they are the immature representatives, it is still convenient in 

 speaking of them to use the old generic names, and Brooks (1886) 

 extended this terminology at the same time that he pointed out distin- 

 guishing characters of the representative larval forms of most of the 

 genera, so that now for each one of the j)rincipal adult genera we liav^e a 

 corresponding larval type. The ontogeny of Protosqiiilla, Pterygo- 

 sqiiilla. and LeptosiiuiUa is unknown. The chief characteristics of the 

 larval forms of the other genera are displayed in the following: 



AXALYTICAL KEY TO THE TYPES OF STOMATOI'OI) EAKV.E. 



I. Eyes sessile; aiipendages l-x (leveki])e(l and xiv-xvii also Imdded in older 



stages Ekichthoidixa, Clatis. (Au early stage; a<lult Ibrm 



unknown). 



II. Eyes stalked; appendages i-vii and xiv-xvii, present in earliest stages. 



* Erichthtis Form: Telsou usually quadrate or licxagonal in general (nitline. 

 with never more than 1 intermediate denticles. 

 t Body elongated; carapace narrow without prominent ventro-lateral angles 

 and with posterior lateral angles near the dorsal surface. 

 Telson slightly wider than long, and notched on the median line; pos- 

 terior lateral spines of carapace long; never any trace of lateral 

 teeth ux)on the raptorial dactylus. 



GoxEKicHTHUS, Brooks. (Larva of (ioxoDACTVLUS). 

 Like the above, but the dactylus of the raptorial limb showing traces of 

 ■ lateral teeth in the oldest stages. 



Odoxtekichthus, new type. (? Larva of Odontodactylus). 

 Hind body very long; telson longer than wide, sometimes ovate in gen- 

 eral outline; carapace narrow and short witli short rostrum and 

 short jiostero-lateral spines: 



Pseuderichthcs, Brooks. (Larva of PsEiDOsgriLLA), 



